Almost exactly a year ago, we heard from some of our publishers that their apps were being rejected from the AppStore because they were using the iOS UDID . This created a stir. There was a strong reason to move away from UDID: it had clear privacy issues and there was no way for consumers to opt-out of targeted advertising or change their identifier. However, without UDID, most conversion tracking features would break, likely negatively impacting advertising revenue. As a result, it was a poor solution. In the spring last year, we advocated for a replacement , which we got in iOS6: the Identifier for Advertising (IDFA). We immediately threw our support behind this improved identifier .
Recently, Apple announced that as of May 1st, 2013, any new apps or updates submitted to the iOS AppStore using UDID will be rejected.
As a result, our client engineering team pushed an update to our open source MoPub client GitHub repository removing its remaining references to UDID . (Prior to today’s update, we were passing hashed UDID on iOS5 and below.) We also decided not to replace it with ODIN, as we concluded that this alternative approach is also not respectful of user privacy.
Our data indicate that 19% of our iOS users are on iOS 5 or lower. However, since this only applies to new apps and updates, our forecasts show that one month after the SDK’s release about 2% of our iOS users will not be passing any identifier. After three months, the figure will be roughly 6%, after which time we expect the majority of remaining iOS5 users to update to iOS6 or new devices.
MoPub remains committed to helping our publishers and demand partners with the transition to IDFA. We are happy to be able to put the confusion around UDID and its related privacy concerns firmly in the past.