Apps not using UDID data willl see 24% less ad revenue, study says

MoPub notes that because mobile advertisers use unique device identifier (UDID) data to track an ad's effectiveness to create pricing models, the removal of such a tool would likely result in app developers losing nearly a quarter of all ad revenue, according to a Wednesday report from MacWorld UK.

In the traditional mobile ad system, iOS app publishers use UDID data as both a means of performance measurement and monetization while advertisers rely on the data to see how well an ad converts into an action like downloads or click-throughs. The ad companies are basically testing an advertisement's effectiveness and value to decide how much to pay app publishers for ad space.

“The move away from UDIDs threatens advertising revenue that many publishers depend on in order to support their content creation and businesses," said MoPub CEO and co-founder Jim Payne. "Here, we see a direct correlation between the money paid for an ad and the ability to track an ad. It’s clear that Apple needs to address this issue with an appropriate alternative, because the damage to a publisher’s bottom line will likely be material if UDID data actually disappears.”

MoPub's three month study found that the disparity between publishers which use UDIDs and those that do not is an eCPM (effective cost per mille) average of 0.18 cents with app makers pulling in 0.76 cents and 0.58 cents, respectively.

UDID data usage has been a hot-button topic as mobile privacy issues have come under the scrutiny of consumers and lawmakers alike. Other means of transmitting sensitive personal information without the knowledge or consent of users raised enough attention that Congress members of the U.S. House Committee on Energy and Commerce sent a series of letters to Apple CEO Tim Cook asking about what the company was doing to ensure the security of iPhone and iPad owners. The subcommittee went as far as requesting that an Apple representative be dispatched to Washington for a briefing on the company's app developer policies and practices.

An example of unauthorized data transmission is social networking app Path's back-end "feature" that copied a user's contacts and sent the information to off-site servers in the name of streamlining the process in which the service connects users. Path ultimately apologized and implemented an opt-in system for uploading address data.

Apple first addressed the UDID issue in August 2011 when it announced plans to remove app publishers' access to the data in iOS 5, though the functionality has yet to be eschewed and remains in the latest version 5.1.

It was reported in late March that Apple was gearing up to initiate blanket rejections of apps using UDID data in an effort to deprecate all third-party UDID access, though there has been no official word that this is the case.