One of the most common questions we’re asked at Apsalar is to explain IDFA, the advertising ID in iOS (iPhone) phones. Given that, I thought I’d put out a short and simple explanation here.
IDFA is the abbreviation for identifier for advertisers on iPhones. An IDFA is somewhat analogous to an advertising cookie, in that it enables an advertiser to understand that a user of a particular phone has taken an action like a click or an app install. IDFAs take on the tracking role for mobile that cookies play in the PC web because cookies are problematic in the mobile world. For more information on why cookies don’t work in mobile, download Why Do They Say Cookies Don’t Work in Mobile? from the resources section on our site.
Semi-Persistent Device Identifiers
Advertisers are naturally interested in understanding the anonymized individuals that take advertising actions. IDFAs (and their Android siblings, Android Advertising IDs) help an advertiser identify the specific phone where the ad action takes place.
Third party cookies, which are commonly used on the PC web for tracking, tend to have short life spans – anything from 1 to 30 days on average. By contrast, the IDFA doesn’t change unless a user decides to change it in their phone settings. Few consumers feel a need to take this action, so IDFAs can offer a better foundation for a persistent and anonymized consumer profile.
Also, an IDFA device advertising ID is the same for all of the apps and browsers on a phone, so it can be a powerful way to aggregate customer behavior across all of these disconnected environments. Thus, device IDs like IDFA are very useful as the foundation for customer profiles in data management platforms, or DMPs. They enable a brand to accurately aggregate data about a customer to a specific, anonymized profile.
Before IDFA, advertisers could track actions on iPhones using a device identifier called UDID or universal device ID. The big advantage that IDFA offers over UDID is consumer choice. Apple introduced IDFA to offer consumers a choice when it came to interest advertising and tracking. A UDID was a permanent device number, and sharing it could not be turned off, whereas users have the option to opt out of IDFA tracking, or to change their IDFA periodically.
IDFA is the only ID that Apple allows advertisers to use to understand the advertising actions on its phones. This reflects their commitment to the ideas of privacy and choice, while also enabling a robust advertising industry in which brands target likely responders and drive revenue for app and mobile web publishers.
Using IDFA
When consumers take actions as a result of ads, like clicking a banner, playing a video, or installing an app, media companies can pass the IDFA with information about the consumer action that took place as a result of the advertising. The IDFA enables an advertiser to individually target specific individuals that have taken actions in the past. This sort of individual targeting is becoming increasingly common as programmatic media and social media advertising grow in popularity.
You may also occasionally hear about an ID called IDFV, This stands for Identifier for Vendors. An IDFV is assigned and shared by all apps from the same company. Sometimes companies with multiple apps base their marketing efforts and analyses on IDFV, because they only change if a user uninstalls all apps from a particular vendor.
You can find more specifics about IDFA here and here.