|Type of business||Subsidiary|
|Headquarters||New York City, U.S.|
|Key people||Jeff D'Onofrio (CEO)|
|Industry||Microblogging, social networking service|
|Employees||411 (as of June 2017)|
|Parent||Yahoo! Inc. (2013–2017)|
Verizon Media (2017–present)
|Alexa rank||79 (July 2019[update])|
Tumblr (stylized as tumblr and pronounced "tumbler") is a microblogging and social networking website founded by David Karp in 2007 and owned by Verizon Media. The service allows users to post multimedia and other content to a short-form blog. Users can follow other users' blogs. Bloggers can also make their blogs private. For bloggers many of the website's features are accessed from a "dashboard" interface.
- 1 History
- 2 Features
- 3 Usage
- 4 Corporate affairs
- 5 Criticism
- 6 Recognition
- 7 See also
- 8 References
- 9 External links
Development of Tumblr began in 2006 during a two-week gap between contracts at David Karp's software consulting company, Davidville (housed at Karp's former internship with producer-incubator Fred Seibert's Frederator Studios, which was located a block from Tumblr's current headquarters). Karp had been interested in tumblelogs (short-form blogs) for some time and was waiting for one of the established blogging platforms to introduce their own tumblelogging platform. As no one had done so after a year of waiting, Karp and developer Marco Arment began working on their own tumblelogging platform. Tumblr was launched in February 2007, and within two weeks the service had gained 75,000 users. Arment left the company in September 2010 to focus on Instapaper.
In early June 2012, Tumblr featured its first major brand advertising campaign in conjunction with Adidas, who launched an official soccer Tumblr blog and bought placements on the user dashboard. This launch came only two months after Tumblr announced it would be moving towards paid advertising on its site.
On May 20, 2013, it was announced that Yahoo and Tumblr had reached an agreement for Yahoo! Inc. to acquire Tumblr for $1.1 billion in cash. Many of Tumblr's users were unhappy with the news, causing some to start a petition, achieving nearly 170,000 signatures. David Karp remained CEO and the deal was finalized on June 20, 2013. Advertising sales goals were not met and in 2016 Yahoo wrote down $712 million of Tumblr's value.
Karp announced in November 2017 that he would be leaving Tumblr by the end of the year. Jeff D'Onofrio, Tumblr's President and COO, took over leading the company.
The site, along with the rest of the Oath division (renamed Verizon Media Group in 2019), has continued to struggle under Verizon. In March 2019, SimilarWeb estimated Tumblr had lost 30% of its user traffic since December 2018, when the site had introduced a stricter content policy with heavier restrictions on adult content (which had been a notable draw to the service). In May 2019, it was reported that Verizon was considering selling the site due to its continued struggles since the purchase (as it had done with another Yahoo property, Flickr, via its sale to SmugMug). Following this news, Pornhub's vice president publicly expressed interest in purchasing Tumblr, with a promise to reinstate the previous adult content policies.
- Dashboard: The dashboard is the primary tool for the typical Tumblr user. It is a live feed of recent posts from blogs that they follow. Through the dashboard, users are able to comment, reblog, and like posts from other blogs that appear on their dashboard. The dashboard allows the user to upload text posts, images, video, quotes, or links to their blog with a click of a button displayed at the top of the dashboard. Users are also able to connect their blogs to their Twitter and Facebook accounts; so whenever they make a post, it will also be sent as a tweet and a status update.
- Queue: Users are able to set up a schedule to delay posts that they make. They can spread their posts over several hours or even days.
- Tags: Users can help their audience find posts about certain topics by adding tags. If someone were to upload a picture to their blog and wanted their viewers to find pictures, they would add the tag #picture, and their viewers could use that word to search for posts with the tag #picture.
- HTML editing: Tumblr allows users to edit their blog's theme HTML coding to control the appearance of their blog. Users are also able to use a custom domain name for their blog.
With Tumblr's 2009 acquisition of Tumblerette, an iOS application created by Jeff Rock and Garrett Ross, the service launched its official iPhone app. The site became available to BlackBerry smartphones on April 17, 2010, via a Mobelux application in BlackBerry World. In June 2012, Tumblr released a new version of its iOS app, Tumblr 3.0, allowing support for Spotify, hi-res images and offline access. An app for Android is also available. A Windows Phone app was released on April 23, 2013. An app for Google Glass was released on May 16, 2013.
Inbox and messaging
Tumblr blogs may optionally allow users to submit questions, either as themselves or anonymously, to the blog for a response. Tumblr also offered a "fan mail" function, allowing users to send messages to blogs that they follow.
On November 10, 2015, Tumblr introduced an integrated instant messaging function, allowing users to chat between other Tumblr users. The feature was rolled out in a "viral" manner; it was initially made available to a group of 1500 users, and other users could receive access to the messaging system if they were sent a message by any user that had received access to the system itself. The messaging platform replaces the fan mail system, which was deprecated. The ability to send posts to others via the Dashboard was added the following month.
In May 2012, Tumblr launched Storyboard, a blog managed by an in-house editorial team which features stories and videos about noteworthy blogs and users on Tumblr. In April 2013, Storyboard was shut down.
In March 2018, Tumblr began to syndicate original video content from Verizon-owned video network go90, as part of an ongoing integration of Oath properties, and reported plans to wind down go90 in favor of using Oath properties to distribute its content instead. This made the respective content available internationally, since go90 is a U.S.-only service.
This section may lend undue weight to certain ideas, incidents, or controversies. (February 2017) (Learn how and when to remove this template message)
In 2011, the service was most popular with the teen and college-aged user segments with half of Tumblr's visitor base being under the age of 25. In April 2013, the website received more than 13 billion global page views. User activity, measured by the number of blog posts each day, peaked at over 100 million in early 2014 and declined in each of the next three years, to approximately 30 million by October 2018.
Tumblr has been noted by technology journalists as having a sizable amount of pornographic content. An analysis conducted by news and technology site TechCrunch on May 20, 2013 has shown that over 22% of all traffic in and out of Tumblr was classified as pornography. In addition, a reported 16.45% of blogs on Tumblr exclusively contained pornographic material.  Since July 2013 and its acquisition by Yahoo, Tumblr has progressively restricted adult content on the site. In July 2013, Tumblr began to filter content from adult-tagged blogs from appearing in search results and tag displays unless the user is logged in. In February 2018, Safe Mode (which filters "sensitive" content and blogs) became enabled by default for all users on an opt-out basis.
On December 3, 2018, Tumblr announced that effective December 17, all images and videos depicting sex acts, and real-life images and videos depicting human genitalia or "female-presenting" nipples, would be banned from the service. Exceptions are provided for illustrations or art that depict nudity, nudity related to "political or newsworthy speech", and depictions of "female-presenting" nipples in relation to medical events such as childbirth, breastfeeding, mastectomy and gender reassignment surgery. The new rules do not apply to text content. All posts in violation of the new policy will be hidden from public view, and repeat offenders may be reprimanded. Shortly prior to the announcement, Tumblr's Android app was patched to remove the ability to disable Safe Mode.
The change has faced wide criticism among Tumblr's community; in particular, it has been argued that the service should have focused on other major issues (such as controlling hate speech or the number of porn-related spambots on the service), and that the service's adult community provided a platform for sex education, independent adult performers (especially those representing LGBT communities who feel that they are underrepresented by a heteronormative mainstream industry) seeking an outlet for their work, and those seeking a safe haven from "over-policed" platforms to share creative work with adult themes. Tumblr stated that it is using various algorithms to detect potential violations, in combination with manual reviews. Users quickly discovered a wide array of false positives. A large number of users scheduled protest actions on the 17th.
On the day the ban took effect, Tumblr issued a new post clarifying the new policy, showcasing examples of adult images still allowed on the service, and stating that it "fully recognized" its "special obligation" to serving its LGBT userbase, and that "LGBTQ+ conversations, exploration of sexuality and gender, efforts to document the lives and challenges of those in the sex worker industry, and posts with pictures, videos, and GIFs of gender-confirmation surgery are all examples of content that is not only permitted on Tumblr but actively encouraged."
Wired cited multiple potential factors in the ban, including that the presence of adult content made the service unappealing to potential advertisers, the Stop Enabling Sex Traffickers Act (a U.S. federal law which makes websites liable for knowingly assisting or facilitating illegal sex trafficking), as well as heavy restrictions on adult content imposed by Apple for software offered on the iOS App Store (which similarly prompted several Reddit clients to heavily frustrate the ability for users to access forums on the site that contain adult content).
Tumblr's headquarters is at 770 Broadway in New York City. The company also maintains a support office in Richmond, Virginia. As of June 1, 2017, Tumblr had 411 employees. The company's logo is set in Bookman Old Style with some modifications.
As of 2011[update] Tumblr had received about $125 million of funding from investors. The company has raised funding from Union Square Ventures, Spark Capital, Martín Varsavsky, John Borthwick (Betaworks), Fred Seibert, Krum Capital, and Sequoia Capital (among other investors).
In its first round of funding in October 2007, Tumblr raised $750,000 from Spark Capital and Union Square Ventures. In December 2008 the company raised $4.5 million in Series B funding and a further $5 million in April 2010. In December 2010 Tumblr raised $30 million in Series D funding. The company had a $800 million valuation in August 2011. In September 2011 the company raised $85 million in a round of funding led by Greylock Partners and Insight Venture Partners.
In an interview with Nicole Lapin of Bloomberg West on September 7, 2012, David Karp said the site was monetized by advertising. Their first advertising launch started in May 2012 after 16 experimental campaigns. Tumblr made $13 million in revenue in 2012 and hoped to make $100 million in 2013. Tumblr reportedly spent $25 million to fund operations in 2012.
In 2013, Tumblr began allowing companies to pay to promote their own posts to a larger audience. Tumblr Head of Sales, Lee Brown, has quoted the average ad purchase on Tumblr to be nearly six figures. Tumblr also allows premium theme templates to be sold for use by blogs.
In July 2016, advertisements were implemented by default across all blogs. Users may opt out, and the service stated that a revenue sharing program would be implemented at a later date.
Tumblr has received criticism for copyright violations by participating bloggers; however, Tumblr accepts Digital Millennium Copyright Act (DMCA) take-down notices. Tumblr's visual appeal has made it ideal for photoblogs that often include copyrighted works from others that are re-published without payment. Tumblr users can post unoriginal content by "Reblogging", a feature on Tumblr that allows users to re-post content taken from another blog onto their own blog with attribution.
Tumblr has been forced to manage spam and security problems. For example, a chain letter scam in May 2011 affected 130,000 users.
On December 3, 2012, Tumblr was attacked by a cross-site scripting worm deployed by the Internet troll group Gay Nigger Association of America. The message urged users to harm themselves and criticized blogging in general.
User interface changes
In 2015, Tumblr faced criticism by users for changes to its reblog mechanisms. In July 2015, the system was modified so that users cannot remove or edit individual comments by other users when reblogging a post; existing comments can only be removed all at once. Tumblr staff argued that the change was intended to combat "misattribution". In September 2015, Tumblr changed how threads of comments on reblogged posts are displayed; rather than a nested view with indentations for each post, all reblogs are now shown in a flat view, and user avatars were also added. The change was intended to improve the legibility of reblogs, especially on mobile platforms, and complements the inability to edit existing comments. Although some users had requested such a change to combat posts made illegible by extremely large numbers of comments on a reblogged post, the majority of users (even those who had requested such a change) criticized the new format. The Verge was also critical of the changes, noting that it was cleaner, but made the site lose its "nostalgic charm".
Promotion of self-harm and suicide
The suicide of a British teenager, Tallulah Wilson, raised the issue of suicide and self-harm promotion on Tumblr as Wilson was reported to have maintained a self-harm blog on the site. A user on the site is reported to have sent Wilson an image of a noose accompanied by the message: "here is your new necklace, try it on." In response to the Wilson case, Maria Miller, the UK's minister for culture, media and sport, said that social media sites like Tumblr need to remove "toxic" self-harm content.
Searching terms like "depression", "anxiety", and "suicide" on Tumblr now brings up a PSA page directing the user to resources like the national suicide lifeline, and 7 Cups; as well as an option to continue to the search results.[better source needed]
There are concerns of some Tumblr posts glorifying suicide and depression among young people.
In February 2018, BuzzFeed published a report claiming that Tumblr was utilized as a distribution channel for Russian agents to influence American voting habits during the 2016 presidential election.
Several countries have blocked Tumblr because of pornography, religious extremism or LGBT content. These countries include China, Indonesia, Kazakhstan and Iran. In February 2016, the Indonesian government temporarily blocked access to Tumblr within the country because the site hosts pages that carried porn. The government shortly reversed its decision to block the site and said it had asked Tumblr to self-censor its pornographic content.
In November 2018, Tumblr's iOS app was pulled by Apple after illegal child pornography images were found on the service. Tumblr stated that all images uploaded to the service are scanned against an industry database, but that a "routine audit" had revealed images that had not yet been added to the database. In the wake of the incident, a number of Tumblr blogs — particularly those dealing primarily in adult-tagged artwork such as erotica, as well as art study and anatomy resources — were also deleted, with affected users taking to other platforms (such as Twitter) to warn others and complain about the deletions, as well as encourage users to back up their blog's contents. Tumblr subsequently removed the ability to disable "Safe Mode" from its Android app, and announced a wider ban on explicit images of sex acts and nudity on the platform with certain limited exceptions.
- In August 2010, Tumblr was named as a finalist in Lead411's New York City Hot 125.
- Celebrities who use Tumblr include Taylor Swift, Lady Gaga, Zooey Deschanel, John Mayer and Zayn.
- On October 21, 2011, Tumblr became the first blogging platform to host Barack Obama's blog.
- Comparison of microblogging services
- Comparison of free blog hosting services
- List of social networking websites
- Tech companies in the New York metropolitan area
- "Press Information". Tumblr. Retrieved May 6, 2019.
- "Press Information". Tumblr. Retrieved June 1, 2017.
- "Tumblr.com Traffic, Demographics and Competitors - Alexa". www.alexa.com.
- Yu, Roger (May 20, 2013). "Yahoo Pledges 'Not to Screw up' Tumblr Deal". USA Today. Retrieved July 2, 2016.
- Liedtke, Michael (May 20, 2013). "Yahoo Takes Big Leap with $1.1B Deal for Tumblr". ABC Action News. Retrieved July 2, 2016.
- Blodget, Henry (May 20, 2013). "Yahoo CEO Marissa Mayer Buys Tumblr–Her Boldest Move Yet". Yahoo Finance. Retrieved July 2, 2016.
- Mayer, Marissa (June 20, 2013). "Tumblr. + Yahoo! – It's Officially Official". Yahoo!. Tumblr. Retrieved July 2, 2016.
- Boutin, Paul (March 13, 2009). "Tumblr Makes Blogging Blissfully Easy". The New York Times. Retrieved March 26, 2009.
- "These 19 Social Networks Are Bigger Than Google+: #10 Tumblr, the Popular Social-Blogging Platform, 6.81 Million". Business Insider. Retrieved July 2, 2016.
- "About Us". Tumblr. Retrieved May 6, 2019.
- Karp, David; Alexandria, Julie (May 27, 2008). David Karp and Tumblr (Video). Wallstrip. Event occurs at 1:30. Retrieved February 24, 2013.
Sometime in 2006, we had a couple of weeks between contracts and said 'Let's see what we can do, let's see if we can build this thing', and we threw together the first working version of Tumblr.
- ""Tumblr: David Karp's $800 Million Art Project" Forbes, January 2, 2013". Forbes.com. April 18, 2012. Retrieved April 17, 2013.
- Davis, Sammy (August 27, 2008). "So What Do You Do, David Karp, Founder of Tumblr?". Mediabistro.com. Archived from the original on January 2, 2013. Retrieved January 2, 2013.
- Shafrir, Doree (January 15, 2008). "Would You Take a Tumblr With This Man?". The New York Observer. Archived from the original on January 2, 2013. Retrieved January 2, 2013.
- Karp, David (December 12, 2011). David Karp: When It All Came Together (Video). Fast Company. Event occurs at 1:03. Retrieved February 24, 2013.
Over the next few months, we kind of pieced together what became the first version of Tumblr which launched in February 2007.
- Karp, David (February 19, 2007). "Tumblr – something we've always wanted". Davidville. Archived from the original on February 24, 2013. Retrieved February 24, 2013.
- Ingram, Matthew (August 25, 2010). "Google VC, Tumblr CEO Among the Top Innovators Under 35". GigaOM. Giga Omni Media. Archived from the original on January 2, 2013. Retrieved January 2, 2013.
- Frommer, Dan (September 21, 2010). "Tumblr CTO Steps Down To Focus on Instapaper, Independent Career". Business Insider. Retrieved February 24, 2013.
- Delo, Cotton (June 8, 2012). "Tumblr Unveils First Major Brand Campaign for Adidas". Advertising Age. Crain Communications. Archived from the original on July 18, 2012. Retrieved July 18, 2012.
- Yahoo to buy Tumblr for $1.1 billion: Report, CNN.com. Retrieved May 21, 2013.
- "Yahoo's Board Approves $1.1 Billion Purchase of Tumblr". Business Insider. Retrieved May 19, 2013.
- Lunden, Ingrid. "Hell No, Tumblr Users Won't Go To Yahoo!". Techcrunch. Retrieved May 20, 2013.
- Mayer, Marissa (May 20, 2013). "Tumblr. + Yahoo! = !!". Retrieved May 20, 2013.
- "Yahoo! to Acquire Tumblr" (Press release). Yahoo!. May 20, 2013. Retrieved May 20, 2013.
- Fiegerman, Seth (July 18, 2016). "Yahoo 'screws it up,' writes down $482 million of Tumblr". CNNMoney. Retrieved December 18, 2017.
- Goel, Vindu (June 13, 2017). "Verizon completes $4.48 billion purchase of Yahoo, ending an era". The New York Times. Retrieved December 18, 2017.
- Lunden, Ingrid (November 28, 2017). "David Karp is leaving Tumblr". Archived from the original on November 28, 2017. Retrieved November 28, 2017.
- Liao, Shannon (March 14, 2019). "After the porn ban, Tumblr users have ditched the platform as promised". The Verge. Retrieved March 14, 2019.
- Welch, Chris (May 2, 2019). "Verizon is looking to sell Tumblr after squandering its potential". The Verge. Retrieved May 3, 2019.
- Brodkin, Jon (May 3, 2019). "Pornhub wants to buy Tumblr and restore site to former porn-filled glory". Ars Technica. Retrieved May 3, 2019.
- "Cumulative total of Tumblr posts between May 2011 and April 2013 (in billions)". Statista. Retrieved May 21, 2013.
- "Tumblr Help: Posts". Tumblr.com. Retrieved January 27, 2014.
- Van Grove, Jennifer (February 25, 2009). "Tumblr Rebrands Tumblerette and Releases Free iPhone App". Retrieved March 22, 2011.
- "Tumblerette is now the official Tumblr iPhone App! (and it's free!)". February 25, 2009. Retrieved March 22, 2011.
- Perez, Sarah (June 21, 2012). "Better, Stronger, Faster: Tumblr 3.0 For iPhone Has Arrived". TechCrunch. Archived from the original on July 18, 2012. Retrieved July 18, 2012.
- Kerr, Dara (April 8, 2013). "Tumblr rolls out its newfangled Android app". CNET. Archived from the original on April 24, 2013. Retrieved April 24, 2013.
- Welch, Chris (April 23, 2013). "Tumblr comes to Windows Phone with lock screen, live tile enhancements". The Verge. Archived from the original on April 24, 2013. Retrieved April 24, 2013.
- Tibken, Shara (May 16, 2013). "Google: Check out our new Glassware like Tumblr". CNET. CBS Interactive. Archived from the original on May 17, 2013. Retrieved May 17, 2013.
- "Tumblr releases Fan Mail for private messaging". VentureBeat. January 4, 2012. Retrieved November 11, 2015.
- "Tumblr Rolls Out Instant Messaging On Both Web And Mobile". TechCrunch. AOL. Retrieved November 11, 2015.
- "Tumblr launches instant messaging on Android, iOS, and the web". The Verge. Vox Media. November 10, 2015. Retrieved November 11, 2015.
- Swanner, Nate (December 10, 2015). "Tumblr now lets you send posts as messages, and supports Live Photos on iOS". The Next Web. Retrieved April 24, 2018.
- Weber, Harrison (May 7, 2012). "Tumblr's editorial hires lead to "Storyboard," a hub to feature creative users". The Next Web. Archived from the original on April 13, 2013. Retrieved April 13, 2013.
- Faircloth, Kelly (April 9, 2013). "Tumblr Kills Storyboard; Editorial Employees Will Be 'Moving On'". Betabeat. Archived from the original on April 13, 2013. Retrieved April 13, 2013.
- "With Go90 flatlining, Verizon sees Tumblr as home to original digital video programs". Digiday. April 20, 2018. Retrieved April 24, 2018.
- Roettgers, Janko (February 13, 2018). "Oath CEO Tim Armstrong Casts Doubt on Future of Go90". Variety. Retrieved April 24, 2018.
- Lipsman, Andrew (August 30, 2011). "Tumblr Defies its Name as User Growth Accelerates". comScore. Archived from the original on January 6, 2012. Retrieved January 6, 2012.
- MacMillan, Douglas (May 19, 2013). "Yahoo's board approves $1.1 billion purchase of Tumblr, WSJ says". The Washington Post. Retrieved May 20, 2013.
- "Tumblr: Total number of posts 2018 | Statistic".
- Kafka, Peter (May 18, 2013). "Why Yahoo Doesn't Think Tumblr Has a Porn Problem". All Things Digital. Archived from the original on June 16, 2013. Retrieved June 16, 2013.
- de la Merced, Michael J.; Bilton, Nick; Perlroth, Nicole (May 19, 2013). "Yahoo to Buy Tumblr for $1.1 Billion". The New York Times. The New York Times Company. p. A1. Archived from the original on June 16, 2013. Retrieved June 16, 2013.
- "Tumblr's Adult Fare Accounts For 11.4% Of Site's Top 200K Domains, Adult Sites Are Leading Category Of Referrals". TechCrunch. May 20, 2013.
- "Tumblr Is Turning 'Safe Mode' on by Default for Everyone". Motherboard. February 8, 2018. Retrieved December 4, 2018.
- "Tumblr will ban all adult content on December 17th". The Verge. Retrieved December 3, 2018.
- "Adult content". Tumblr Help Center. Retrieved December 3, 2018.
- Martineau, Paris (December 4, 2018). "Tumblr's Porn Ban Reveals Who Controls What We See Online". Wired. ISSN 1059-1028. Retrieved December 9, 2018.
- "Apple Sucked Tumblr Into Its Walled Garden, Where Sex Is Bad". Motherboard. December 3, 2018. Retrieved December 4, 2018.
- "Verizon takes aim at Tumblr's kneecaps, bans all adult content". Ars Technica. Retrieved December 4, 2018.
- Stephen, Bijan (December 6, 2018). "Tumblr's porn ban could be its downfall — after all, it happened to LiveJournal". The Verge. Retrieved December 6, 2018.
- Rogers, Kaleigh; Koebler, Jason (December 4, 2018). "Tumblr's Algorithm Thinks Vomiting Unicorns, Raw Chicken, and Boot Cleaners Are Porn". Motherboard. Retrieved December 6, 2018.
- Radulovic, Petrana (December 4, 2018). "Tumblr's wonky algorithm is flagging innocent posts as adult content". Polygon. Retrieved December 6, 2018.
- Matsakis, Louise (December 5, 2018). "Tumblr's Porn-Detecting AI Has One Job—and It's Bad at It". Wired. ISSN 1059-1028. Retrieved December 6, 2018.
- Radulovic, Petrana (December 17, 2018). "Tumblr users are logging off to protest new guidelines, but will it work?". Polygon. Retrieved December 18, 2018.
- "As adult content ban arrives, Tumblr clarifies and refines rules". TechCrunch. Retrieved December 18, 2018.
- Goodman, Daniel (January 12, 2012). "Tumblr Office Tour". Business Insider. Retrieved June 10, 2013.
- McGeehan, Patrick (May 9, 2012). "Technology Industry Seen Growing Fastest in New York". New York Times.
- Cocke, Annie; Tatti, Katelyn (March 30, 2012). "Tumblr grows rapidly, moves to larger Richmond office". WTVR-TV. Archived from the original on February 8, 2014. Retrieved February 8, 2014.
- Coles, Stephen (December 3, 2013). "Tumblr Logo, 2007–2013". Fonts in Use. Archived from the original on February 8, 2014. Retrieved February 8, 2014.
- Edwards, Jim. "Here's Tumblr's Total Revenue For 2012 – And How It Will Make A Profit in 2013". Business Insider. Retrieved March 21, 2013.
- "Best Young Tech Entrepreneurs 2009". Retrieved June 25, 2009.
- Anthony Ha, VentureBeat. "Blog startup Tumblr goes bi-coastal with Sequoia Investment." November 12, 2010.
- Dans, Enrique (May 19, 2013). "David Karp y Tumblr: el momento de la verdad". Archived from the original on September 19, 2015. Retrieved September 19, 2015.
- Marshall, Matt (October 22, 2007). "Roundup: Brightroll, Tumblr, Collective, Veeker, MobileEye, all raise cash". VentureBeat. Archived from the original on May 20, 2013. Retrieved May 20, 2013.
- Kafka, Peter (December 11, 2008). "Who Said Web 2.0 Was R.I.P.? Microblog Tumblr Raises $4.5 Million, Expectations". All Things Digital. Dow Jones & Company. Archived from the original on May 20, 2013. Retrieved May 20, 2013.
- Kafka, Peter (April 20, 2010). "Tumblr Raises Another $5 Million From Spark and Union Square. Now It Wants Your Money". All Things Digital. Dow Jones & Company. Archived from the original on May 20, 2013. Retrieved May 20, 2013.
- Lynley, Matthew (December 17, 2010). "Tumblr brings in $30M despite stability woes". VentureBeat. Archived from the original on May 20, 2013. Retrieved May 20, 2013.
- Ludwig, Sean (August 26, 2011). "Tumblr on verge of raising up to $100M with massive $800M valuation". VentureBeat. Archived from the original on January 6, 2012. Retrieved January 6, 2012.
- Ludwig, Sean (September 26, 2011). "Tumblr grabs another $85M in fresh funding". VentureBeat. Archived from the original on January 6, 2012. Retrieved January 6, 2012.
- Lapin, Nicole (September 5, 2012). ""Tumblr Has 'Ways to Go' Before IPO, CEO Says" 9-5-12". Bloomberg West. Retrieved December 13, 2012.
- Frier, Sarah. "Tumblr to Introduce Mobile Advertising to Help Achieve Profit". Bloomberg. Retrieved March 21, 2013.
- Voakes, Greg (August 14, 2013). "How Pixel Union Built a Business on Tumblr Themes". Huffington Post. Retrieved November 21, 2018.
- "Tumblr will allow users to make money from ads". The Verge. July 28, 2016. Retrieved October 21, 2016.
- Edwards, Jim. "Why Tumblr Needs Adult Supervision Right Now". Business Insider.
- "DMCA Copyright Notifications". Tumblr. Retrieved May 20, 2013.
- Edwards, Jim (September 12, 2011). "Why Tumblr Must Kill What Made it Big: Porn and Copyright Violations". CBSNews.com. Retrieved March 28, 2013.
- "Tumblr: A New Way of Blogging". Retrieved March 21, 2013.
- Leyden, John (May 17, 2011). "Tumblr bloggrs ensnared in chain-spam scam". The Register. Retrieved May 19, 2013.
- "Massive worm hits Tumblr, spams big blogs like USA today". CNET. December 3, 2012. Retrieved March 30, 2013.
- "Tumblr users are not happy about the site's new redesign". The Daily Dot. September 2, 2015. Retrieved September 7, 2015.
- "Tumblr reblogs just got a lot cleaner, and a little less charming". The Verge. September 4, 2015. Retrieved September 7, 2015.
- "A New Policy Against Self-Harm Blogs". Tumblr Staff Blog. February 23, 2012. Retrieved January 27, 2014.
- "Maria Miller: Time for a crackdown on social media 'poison'". The Telegraph. January 27, 2014. Retrieved January 27, 2014.
- Hern, Alex (January 27, 2014). "Social networks to face government grilling over suicide content". The Guardian. Retrieved January 27, 2014.
- "Everything okay?". Tumblr. Retrieved May 21, 2016.
- Becker, Mayer, Nagenborg, El-Faddagh, & Schmidt, 2004; Duggan, Heath, Lewis, & Baxter, 2012; Lewis, Heath, St. Denis, & Noble, 2011; Mitchell & Ybarra, 2007; Whitlock, Powers, & Eckenrode, 2006
- Silverman, Craig (February 6, 2018). "Russian Trolls Ran Rampant On Tumblr And The Company Refuses To Say Anything About It". BuzzFeed. Retrieved March 12, 2018.
- "Tumblr's nudity ban removes one of the last major refuges for pornography on social media". Washington Post. December 3, 2018. Retrieved March 26, 2019.
- "Tech in Asia - Connecting Asia's startup ecosystem".
- "Kazakhstan | Astana blocks Tumblr for promoting terrorism, porn". April 12, 2016.
- "Current State of Internet Censorship in Iran - Research - ViewDNS.info".
- Ho, Victoria (February 18, 2016). "Indonesia reverses Tumblr ban, for now". Mashable. Archived from the original on February 29, 2016. Retrieved February 29, 2016.
- "Tumblr was removed from Apple's App Store over child pornography issues". The Verge. Retrieved November 20, 2018.
- "Tumblr's Child Porn Crackdown Ensnares Legit Blogs in Purge". PC Magazine. Retrieved November 21, 2018.
- "NSFW artists speak out as their accounts are suddenly 'purged' on Tumblr". The Daily Dot. November 20, 2018. Retrieved November 21, 2018.
- "New York City Hot 125". Lead411.com. Archived from the original on May 11, 2011. Retrieved December 24, 2011.
- "How Taylor Swift is using Tumblr to create a safe space with her fans". The Independent. November 9, 2017. Retrieved December 12, 2018.
- Hickman, Angela (August 9, 2011). "The Top 10 celebrities on Tumblr". National Post. Archived from the original on January 6, 2012. Retrieved January 6, 2012.
- Kaufman, Gil (July 13, 2016). "Check Out Zayn Malik's Arty New Tumblr". Billboard. Retrieved July 14, 2016.
- Bilton, Nick (October 24, 2011). "Obama Campaign Experiments With Tumblr for '12". New York Times.
|Wikimedia Commons has media related to Tumblr.|