The ODIN companies want to make it possible for people to opt out of having ads targeted using the technology. Some online ad networks, including the two largest, operated by Google (opt out here) and Yahoo (opt out here), already offer this option.
Subramanian believes few people would opt out of mobile ads. He says studies have shown that less than 6 percent of users opt out of Web advertising or frequently delete their cookies. He adds that the ODIN group would also try to “educate” mobile users about the value of not opting out. “If you saw ads that were entirely misaligned with your interests or you always saw the same ads in every app you used, you would have a worse experience,” he argues.
The voluntary efforts of online advertisers to provide opt-outs are generally seen as an effort to deter government regulation on behavioral advertising. However, a study last year by Stanford researchers found that many companies failed to live up to their own opt-out commitments. For example, half of all companies did not delete tracking cookies from the machines of users who opted out.
Ouriel Ohayon, founder and CEO of Appsfire, whose free app helps smart-phone users discover new apps to download and also shows ads to users, doesn’t believe any approach that logs the MAC address from a user’s phone, even ODIN, will be allowed for long. “Using the MAC address is, at best, a temporary buffer until a definitive solution comes up. It is an identifier which, like the UDID, provides private information about the device,” he says. “If Apple is consistent with their policy, it will be deprecated at some point.”
Ohayon’s company is promoting its own alternative, called OpenUDID, which some companies have already publicly backed. OpenUDID uses a random code generated by software that is not linked to the physical characteristics of a device. The first time that code is generated, it is stored—via the operating system’s copy and paste functionality—in a custom clipboard for other apps to access. “We opted for a solution that we believe has more chances to last,” says Ohayon. OpenUDID also has a built-in opt-out mechanism. However, some critics of OpenUDID say Apple may decide that copy and paste functions aren’t suitable for ad tracking either.
Subramanian believes Apple will approve of the ODIN design, and notes that some apps already use it.
But Ohayon says that, even though ODIN appears to have greater support than any of the competing ideas, its supporters are still a minority in the mobile-ad industry. He says the best solution would be for Apple to go further than just blocking use of UDID and to propose its own solution. Similar calls for Apple to build privacy controls into its mobile operating system were made after the social network Path and other apps were found to be copying address books without asking permission.