UDIDs are on the way out, but don’t panic!

donc2b4t-panic21In August of last year, Apple signaled that they would be responding to privacy concerns by deprecating access to the unique device identifier (UDID) functionality in iOS. Deprecation is a way of making certain features obsolete in future versions of a platform, while providing a transitional period.

This week several sources have reported that at least some apps submitted to the App Store are beginning to be rejected for their use of this API, prompting a number of reactions from developers and the mobile app industry at large, with much constructive discussion and a few traces of panic.

At Adfonic, we’ve been engaged with our customers and partners in mobile advertising over the past six months to ensure there is a straightforward path to alternatives to UDID, which we’ll outline in detail below. As always, as we go forward, we’re committed to providing our advertisers, publishers and developers with advice, options and solutions to cut through the panic and help make sense of a complex and rapidly evolving ecosystem.

What is a UDID?

The UDID is a unique code that has been assigned to every iOS device, and remains the same for the lifetime of the device. Apple itself uses this code to help manage App Store purchases, among other things. It has also been available to developers to use for their own purposes, which include user identification, analytics, and in-app advertising.

As the iOS application ecosystem has grown in the past three years, UDID has emerged as the de facto way of enabling a host of functions that make developers’ lives easier. By virtue of its widespread adoption and usefulness in tracking how advertising impacts App Store downloads and purchases, it underpins the ad-funded iOS app economy.

How do UDIDs work in mobile advertising?

Adfonic, like many ad networks, has used UDIDs as the most convenient and ubiquitous way to correlate data linking a tap or click on an ad seen in one app to the subsequent download and installation of the advertised app. This provides advertisers with a conversion rate (the percentage of users that click on the ad who go on to download the app), which is an important metric for understanding the effectiveness of performance-driven advertising.

From this, advertisers (often developers themselves) can derive a Cost Per Install (CPI), and Adfonic’s optimisation technology uses this information as part of an automated feedback loop, meaning that over time the system can learn the circumstances under which an ad is most effective, and reward those publishers whose traffic drives conversions.

What are the concerns over UDID?

We can’t speak for Apple, but it’s likely they are responding to debate over the privacy implications of UDIDs. The identifier is permanent and tied to a particular device in a way that is irrevocable and ultimately does not give the user choice over whether to share it with app developers, and by extension, ad networks and analytics companies.

What is Apple doing?

While it’s important to note that Apple has not made any official statement on their policy, it seems clear that they have started to reject some App Store submissions when the app in question uses the UDID. How widespread this has been is a matter of conjecture.

Even if this policy comes entirely into force, it would only apply to App Store submissions of new applications and updates to existing applications; it is unlikely that Apple would proactively, at this stage, remove an existing application from the App Store. In addition, apps that users have currently installed continue to use UDID for the time being – Apple could potentially break this functionality, but that would require an iOS version update (and even then, users would have to download and install it.)

Read more about Apple’s stance on UDIDs.

So what does that mean for UDIDs?

Our view is that the age of UDIDs is drawing to an end. However, there is likely to be a significant time period – weeks or even months – where UDIDs continue to be in market. It’s very difficult to know exactly how fast the transition will be, and it will in part be driven by the industry’s collective speed in addressing the gap.  At this time we wouldn’t advise new advertisers to roll out a tracking solution that relies entirely on UDID; however, if such a solution is in place, there will be time to implement alternatives.

What alternatives is Adfonic supporting?

Adfonic has been working with industry partners on several alternatives and solutions that enable tracking of iOS app install campaigns in a post-UDID world.

OpenUDID: The OpenUDID project is a free, open source initiative that uses a feature in iOS to share data between applications in order to store a unique identifier. The identifier is generated the first time it is requested by an application. Importantly, though, it can be removed or regenerated and is therefore much better aligned with privacy frameworks such as those detailed by the IAB and MMA, two industry groups that Adfonic is a part of.

We will be supporting the use of OpenUDID for both publishers and advertisers, and will be working with the OpenUDID community to ensure the continued evolution of the standard and implementation.

ODIN: Adfonic has been involved in the Open Device Identification Number (or ODIN) project from an early stage. ODIN prescribes platform-specific approaches for generating reusable device identifiers. For iOS, the ODIN-1 identifier is a cryptographic hash of the device’s WiFi MAC address (an identifier built into the networking chip on the device).

While we share the concerns of others in the industry about the long term viability of the MAC address as a tracking solution – it shares many of the same privacy issues as UDID – this alternative has some immediate traction with developers and exchanges, and is easily implementable for a variety of use cases. Adfonic will be supporting ODIN-1 for both publishers and advertisers, and working with the ODIN group on the evolution of the standard.

Adfonic and AD-X: We’ve been working closely with the smart folks at AD-X (part of Mobile Futures Group) to provide a deep integration with Adfonic. Next week we’ll be rolling out a replacement for our install tracking code that utilizes AD-X technology in conjunction with Adfonic’s tracking capabilities to give advertisers what we believe is the best and broadest install tracking technology in the market.

AD-X is not specifically a UDID replacement, but it provides a way for campaigns to be tracked across both mobile web and in-app inventory, which actually opens up  100% more traffic to our advertisers. We’re very excited about this partnership and will be posting details and SDK downloads on our developer wiki in the coming days.

Third party solutions: We’re aware that many agencies and DSPs are using or developing their own approaches to work in a UDID-less ecosystem. These technologies tend to rely on either cookies and/or HTML5 database storage, or the nascent space of device fingerprinting. Many of these approaches can be seamlessly integrated with Adfonic using our click ID-based conversion tracking services (see our developer wiki for details).

We’re looking to further support this work by introducing specific targeting options, for example to ensure that in-app clicks on a banner open by launching the Safari browser externally, which is necessary if HTTP cookies are required by the implementation. We remain committed to encouraging the fast pace of innovation in this space and encourage advertisers looking at other approaches to get in touch.


What should I do as a publisher?

First, don’t panic. If you’re currently using UDID, there’s no immediate change mandated. However, it’s possible that the next time you submit an update of your application, it will be rejected unless you upgrade your advertising SDK.  So if you’re a publisher or developer using Adfonic to monetise your app, we’re encouraging you to adopt both the OpenUDID and ODIN-1 identifiers outlined above.

We will be releasing a new version of the Adfonic iOS SDK that supports both in the very near future; alternatively, if you use a 3rd party SDK or custom integration approach, you can find all the technical details at the OpenUDID and ODIN project web sites. These changes will ensure your inventory is compatible with as many advertisers as possible.

What should I do as an advertiser?

First (can you guess where we’re going with this?), don’t panic. While the amount of UDID-enabled inventory will wane over time, our platform will ensure that your campaigns are served only where they can be reliably tracked.  We will be updating our install tracking sample code to utilize OpenUDID and ODIN-1 identifiers.

You may also be interested in the Adfonic/AD-X SDK, which has the additional benefit of opening up mobile web inventory to your install tracked campaigns.  Finally, in the event you’re using a third-party or other proprietary approach, it’s highly likely we can support you – feel free to get in touch with our support team if you have any questions.

In conclusion

It’s often been said (in ironic tones) that the problem with open standards is that there are so many of them. But this is, after all, the way the Internet and in fact the whole of the mobile app world has evolved so quickly. While this may seem like an uncertain time, it’s merely another exciting evolution point on the timeline of the app ecosystem.

With cool heads and clear objectives, we’re confident the industry will converge on common practices that not only provide a replacement to UDIDs, but accelerate innovation and adoption within the mobile advertising space.  We’ll keep you updated on our developments in this area and look forward to continuing the conversation.

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