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Identifier for Advertisers

From Wikipedia, the free encyclopedia

Apple's Identifier for Advertisers (IDFA) is a unique random device identifier Apple generates and assigns to every device. It is intended to be used by advertisers to deliver personalized ads and attribute ad interactions for ad retargeting. Users can opt-out of IDFA via the "Limit Ad Tracking" (LAT) setting (and an estimated 20% do).[1]

Starting in iOS 14.5, iPadOS 14.5, and tvOS 14.5, users are prompted to decide whether to opt-in or out of IDFA sharing before apps can query it. This choice can be altered in Settings.[2][3] In May, 2021, Verizon-owned advertisement analytics company Flurry Analytics reported that 96% of US users opted out of IDFA sharing.[4]



Limit Ad Tracking


In iOS 10, Apple introduced "Limit Ad Tracking" setting for users who do not wish to be tracked by advertising networks. If the setting is enabled the system returns a default all-zero id for that device. As of December 2020, it's estimated that approximately 20% of users turn on this setting.[1]

App Tracking Transparency


On September 3, 2020, Apple announced plans to restrict access to IDFA and require websites and apps to obtain an explicit permission from users before being granted access to IDFA. Since January 2021, users and developers could test this change by installing iOS 14 beta release.[5]

In July 2020, Facebook stated that this transparency requirement would likely hurt their advertising targeting.[6] Facebook said that these changes "may render [their tracking] so ineffective on iOS 14 that it may not make sense to offer it on iOS 14" and Facebook apps on iOS 14, including Facebook, WhatsApp, Instagram, Messenger, and others will not collect IDFA on iOS 14.[7][8]

In early September, Apple postponed these restrictions until early 2021.[9]

In December 2020, the Mozilla Foundation expressed support for Apple restricting access to IDFA and asked users to sign a petition to "help strengthen [Apple's] resolve to protect consumer privacy".[10]

On December 15, 2020, Facebook launched a "Speak Up for Small Businesses" campaign against Apple. In this campaign, Facebook purchased full-page advertisements in newspapers and created a web page claiming Facebook tries to help small businesses. This campaign became controversial even within Facebook itself, because some employees thought Facebook was "trying to justify doing a bad thing by hiding behind people with a sympathetic message."[11]

On January 27, 2021, Google announced that when the new requirement goes into effect, a "handful" of Google apps will stop collecting IDFAs (and thus the apps will avoid displaying a prompt for allowing tracking user activity).[12]

In February 2021, Post-IDFA alliance surveyed 600 customers and noted that 38.5% of them said they plan to allow tracking by tapping "yes" in the App Tracking Transparency prompt.[13][14]

On March 18, 2021, Facebook changed its stance. Facebook CEO, Mark Zuckerberg, claimed that these changes might even strengthen Facebook's position "if Apple’s changes encourage more businesses to conduct more commerce on [Facebook's] platforms by making it harder for them to use their data in order to find the customers that would want to use their products outside of [Facebook's] platforms".[15]

On April 1, 2021, the Apple App Store started rejecting apps which used Adjust SDK and attempted to circumvent App Tracking Transparency rules via device fingerprinting (collecting device and usage data to create a unique identifier in order to track the user).[16][17] On April 2, Adjust removed the offending code and app developers might pass App Store review after updating to the new Adjust SDK version.[18][19]

In May, 2021, Verizon-owned advertisement analytics company Flurry reported that 96% of US users opted out of IDFA sharing. Approximately 3% of US users restricted IDFA sharing system-wide.[4]

Unconditional restrictions on Advertising ID sharing


Apple unconditionally disables Apple IDFA sharing for some Apple ID accounts. In this case apps do not display permission prompt and the Settings entry "Allow Apps to Request to Track" is grayed out. Restrictions apply if the Apple ID is:[20]

  • classified as a child account (for example, user's calculated age is less than 18 years old), or
  • managed by an educational institution or organization which limits tracking, or
  • less than 3 days old.

Circumvention attempts


In March 2021, the China Advertising Association announced that it was backing a device fingerprinting system as a work-around for Apple's new IDFA restrictions called CAID.[21] Companies testing the system reportedly include ByteDance and Tencent.[21]

See also



  1. ^ a b "Identifier for Advertisers (IDFA) | Meaning". www.adjust.com. Adjust GmbH. Retrieved 2020-12-25. roughly 20% of iOS users cannot be tracked using the IDFA because they have enabled LAT.
  2. ^ Krasnoff, Barbara (2021-04-26). "How to use iOS 14.5's new app tracking blocker". The Verge. Retrieved 2021-04-27.
  3. ^ "User Privacy and Data Use". Apple Developer. Retrieved 2021-04-26.
  4. ^ a b Axon, Samuel (2021-05-07). "96% of US users opt out of app tracking in iOS 14.5, analytics find". Ars Technica. Retrieved 2021-05-08.
  5. ^ Statt, Nick (2021-01-28). "Apple's next iOS 14 beta will begin forcing developers to ask for permission to track you". The Verge. Retrieved 2021-01-29.
  6. ^ Rodriguez, Salvador (2020-07-30). "Facebook says Apple's iOS 14 changes could hurt its ad targeting". CNBC. Retrieved 2020-07-31.
  7. ^ Cox, Kate (2020-08-26). "iOS 14 privacy settings will tank ad targeting business, Facebook warns". Ars Technica. Retrieved 2020-08-27.
  8. ^ Wagner, Kurt (2020-08-26). "Facebook Says Apple's Changes to iOS Will Dramatically Hurt Ads". Bloomberg. Retrieved 2020-09-08.
  9. ^ Statt, Nick (3 September 2020). "Apple delays privacy feature that would let iPhone owners keep ad tracking at bay". The Verge. Retrieved 16 September 2020.
  10. ^ "Mozilla Urges Users to Support Apple's Planned Anti-Tracking Changes: 'A Huge Win for Consumers'". MacRumors. Retrieved 2020-12-17.
  11. ^ "Facebook Says It's Standing Up Against Apple For Small Businesses. Some Of Its Employees Don't Believe It". BuzzFeed News. Retrieved 2020-12-25.
  12. ^ "Google to Stop Collecting Advertising Identifiers in iOS Apps in Response to iOS 14's Upcoming Tracking Prompt". MacRumors. Retrieved 2021-01-28.
  13. ^ "Almost 2 in 5 consumers say they'll provide IDFA access". No IDFA? No Problem. 2021-03-16. Retrieved 2021-05-20.
  14. ^ "Advertisers flee to Android as majority of iOS users opt out of ad tracking". AppleInsider. Retrieved 2021-05-20.
  15. ^ Axon, Samuel (2021-03-19). "Zuckerberg: Facebook could be in "stronger position" after Apple tracking change". Ars Technica. Retrieved 2021-03-19.
  16. ^ Koetsier, John. "Apple Rejecting Apps With Fingerprinting Enabled As iOS 14 Privacy Enforcement Starts". Forbes. Retrieved 2021-04-03.
  17. ^ Axon, Samuel (2021-04-02). "New wave of App Store rejections suggests iOS 14.5, new iPad may be imminent". Ars Technica. Retrieved 2021-04-03.
  18. ^ "Version 4.28.0 by nonelse · Pull Request #526 · adjust/ios_sdk". GitHub. Retrieved 2021-04-04.
  19. ^ "Apple Now Rejecting App Updates That Defy iOS 14.5 App Tracking Transparency Rules". MacRumors. Retrieved 2021-04-04.
  20. ^ "Apple Explains Why 'Allow Apps to Request to Track' May Be Grayed Out on iOS 14.5". MacRumors. Retrieved 2021-04-29.
  21. ^ a b McGee, Patrick; Yang, Yuan (March 16, 2021). "TikTok wants to keep tracking iPhone users with state-backed workaround". Ars Technica. Retrieved March 28, 2021.