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Blekko Screenshot.png
Blekko home page
Type of site
Search engine
Available inEnglish
OwnerIBM (International Business Machines)
LaunchedNovember 1, 2010
Current statusDefunct (March 27, 2015)

Blekko, trademarked as blekko (lowercase),[1] was a company that provided a web search engine with the stated goal of providing better search results than those offered by Google Search, with results gathered from a set of 3 billion trusted webpages and excluding such sites as content farms. The company's site, launched to the public on November 1, 2010, used slashtags to provide results for common searches. Blekko also offered a downloadable search bar. It was acquired by IBM in March 2015, and the service was discontinued.


The company was co-founded in 2007 by Rich Skrenta, who had created Newhoo, which was acquired by Netscape and renamed as the Open Directory Project.[2] Blekko raised $24 million in venture capital from such individuals as Netscape founder Marc Andreessen and Ron Conway, as well as from U.S. Venture Partners and CMEA Capital.[3] The company's goal was to be able to provide useful search results without the extraneous links often provided by Google. Individuals who enter searches for such frequently searched categories as cars, finance, health and hotels received results prescreened by Blekko editors who used what The New York Times described as "Wikipedia-style policing" to weed out pages created by content farms and focus on results from professionals.[4] Use of slashtags restricted the set of search results to those matching the specified characteristic and a slashtag was to be automatically added for search categories with prescreened results.[5] This use of slashtag is also implemented in the access of videos and images because Blekko did not have the option to search specific databases for these contents.[6]

Queries related to personal health were limited to a prescreened list of sites that Blekko editors had determined to be trustworthy, excluding many sites that rank highly in Google searches.[2] As of Blekko's launch date, its 8,000 beta editors had developed 3,000 slashtags corresponding to the site's most frequent searches.[5] The company hoped to use editors to develop prepared lists of the 50 sites that best match its 100,000 most frequent search targets.[2] Additional tools allowed users to see the IP address that a website is running on and let registered users label a site as spam.[7]

Blekko also differentiated itself by offering richer data than its competitors. For instance, if a user accessed a domain name with the added /seo, he would be directed to a page containing the statistics of the URL.[8] This is the reason experts cited Blekko's fitness with the Big Data paradigm since it gathers multiple data sets and presents them visually so that the user is provided with quick, meaningful, and actionable information.[9]

At the time, Blekko announced plans to earn revenue by selling ads based on slashtags and search results. The company also planned to provide data on its algorithm for ranking search results, including details for inbound links to specific sites.[4]

As part of a permanent post in Blekko's help section was the following "Web search bill of rights":[10]

  1. Search shall be open
  2. Search results shall involve people
  3. Ranking data shall not be kept secret
  4. Web data shall be readily available
  5. There is no one-size-fits-all for search
  6. Advanced search shall be accessible
  7. Search engine tools shall be open to all
  8. Search and community go hand-in-hand
  9. Spam does not belong in search results
  10. Privacy of searchers shall not be violated

One writer referred to the bill of rights as "what we assume is a poke at Google".[11][12]

In 2011 Blekko announced blocking "content farmy sites", to reduce spam, in line with its bill of rights.[13]

In May 2012 Mozilla announced an "instant search" browser plugin for Firefox designed to cache repetitive search requests, in partnership with Blekko.[14]

In August 2012 Blekko put all its SEO statistics behind a paywall,[15] despite previously declaring that "ranking data shall not be kept secret"[12] in its bill of rights.[15]

Acquisition and closure[edit]

IBM bought Blekko and closed the search service on 27 March 2015, redirecting searches to a page announcing "The blekko technology and team have joined IBM Watson!" and linking to a blog post announcing that the blekko service was closed, with blekko's web-crawling abilities to be integrated into IBM Watson, adding advanced Web-crawling, categorization and intelligent filtering technology.[16]


Blekko used an initiative called slashtags,[1] consisting of a text tag preceded by a "/" slash character, to allow ease of searching and categorise searches. System and pre-defined slashtags allowed users to start searching right away. Users could create slashtags after signup, to perform custom-sorted searches and to reduce spam.[4]


The following features were available to all users:


Blekko offered a downloadable browser toolbar or search bar which changes default search and home page URLs of the user's web browsers.[17]


In 2010, John Dvorak described the site as adding "so much weird dimensionality" to search, and recommended it as "the best out-of-the-chute new engine I've seen in the last 10 years".[7] In Matthew Rogers' review of the site, he found it "slow and cumbersome", and stated that he did not understand the necessity or utility for slashtags.[18] In his review, Jeffrey L. Wilson expressed approval of some search results, but criticized the site's social features which "bog down the search experience."[19]


  1. ^ a b "About". Archived from the original on November 11, 2010. Retrieved December 18, 2011.
  2. ^ a b c Efrati, Amir. "Start-Up Aims at Google: Taps Users to Narrow Results, Avoid Spam Sites", The Wall Street Journal, November 1, 2010. Accessed October 31, 2010.
  3. ^ Wollman, Dana (November 2, 2010). "Blekko launches human-driven search engine". News & Record. Associated Press. Retrieved November 3, 2010.
  4. ^ a b c Miller, Claire Cain. "A New Search Engine, Where Less Is More". The New York Times, October 31, 2010. Accessed October 31, 2010.
  5. ^ a b Van Grove, Jennifer. "Alternative search engine Blekko launches", CNN, November 1, 2010. Accessed November 1, 2010.
  6. ^ Bradley, Phil (2013). Expert Internet Searching. London: Facet Publishing. p. 72. ISBN 9781856046053.
  7. ^ a b Dvorak, John C. "Blekko: The Newest Search Engine", PC Magazine, November 1, 2010. Accessed November 1, 2010.
  8. ^ Warden, Pete (2011). Data Source Handbook: A Guide to Public Data. Sebastopol, CA: O'Reilly Media, Inc. p. 2. ISBN 9781449303143.
  9. ^ Ohlhorst, Frank (2012). Big Data Analytics: Turning Big Data Into Big Money. Hoboken, NJ: John Wiley & Sons. p. 14. ISBN 9781118147597.
  10. ^ "What is Blekko" Archived November 7, 2012, at the Wayback Machine. Retrieved September 22, 2013.
  11. ^ Hales, Paul (November 1, 2010). "New Search Engine Takes a Shot at Google". Thinq.
  12. ^ a b Jeffries, Adrianne (February 1, 2011). "Upstart Search Engine Blekko Blocks Demand Media and Other "Content Farms"". The New York Observer.
  13. ^ Schonfeld, Erick (January 31, 2011). "Blekko Bans Content Farms Like Demand Media's eHow From Its Search Results". TechCrunch.
  14. ^ Rosenblatt, Seth (May 22, 2012). "Firefox flirts with Blekko for 'instant' search".
  15. ^ a b c Keays, Roger (August 14, 2012). "Blekko Paywall Their /SEO Secrets". Retrieved August 15, 2012.
  16. ^ "Data, Data, Everywhere Data. Now a Better Way to Understand It". IBM. March 27, 2015. Retrieved March 27, 2015.
  17. ^ Watson, Cheralyn (January 12, 2012). "How do I remove blekko as my homepage and default search engine in Internet Explorer (IE)?". Archived from the original on April 20, 2012. Retrieved April 10, 2012.
  18. ^ Rogers, Matthew (November 1, 2010). "Blekko, the "Slashtag" search engine is slow, cumbersome, and just plain broken".
  19. ^ Wilson, Jeffrey L. (November 3, 2010). "Blekko".

External links[edit]