Mobile ad network AdMob soon will not serve ads requested from iPhone applications that use ad network mediation layers such as AdWhirl and Tapjoy.

The policy change, effective July 22, was announced yesterday in a company blog post authored by AdMob vice president of product management Ali Diab. The decision has set the industry abuzz. Here is Mr. Diab's post in its entirety:

AdMob policy change: Mediation layers for iPhone applications June 24, 2009
Beginning July 22, AdMob will no longer serve ads requested from iPhone apps that employ ad network mediation layers such as AdWhirl or Tapjoy.

This change will enable us to provide our publishers and advertisers, as well as end users, with the best possible experience and results.

Over the past few months, we have discovered that iPhone apps that use a mediation layer generate a substantially higher volume of complaints from end users and higher number of technical issues than apps that integrate with AdMob directly.

These user complaints and issues range from ads not rendering properly to ads clicking to nowhere to ads taking a very long time to load. Regardless of the type of issue, all damage the end-user experience of both the ad itself and the app within which the ad is displayed.

What we have also found over the last few months is that mediation layers significantly impair AdMob's ability to optimize the selection of ads for the apps that choose to use them, by obstructing our view of these applications' traffic profiles.

These traffic profiles are a key input parameter that we use at AdMob to select the right ad for the right app at the right time.

By working directly with the publisher, AdMob is able to generate a much more accurate profile of the traffic, in terms of both volume and timing, generated by a specific iPhone app, which will enable us to optimize the revenue potential that we can deliver for the app.

At AdMob, we understand that iPhone app developers need to maximize the revenue potential of their apps, even if it means they use multiple ad networks.

To that end, some of our publishers have developed their own logic to allow the use of multiple networks and maximize fill rates, which we will continue to support.

We believe we can best help publishers maximize the revenue potential of their apps by working with them directly.

AdMob is the leader in monetizing iPhone applications with advertising, and we have gained that position by developing sophisticated and highly scalable technologies that enable us to interpret millions of different pieces of information across our network to select the best possible ad for any given ad request.

The proof is in what we deliver for our publishers, with greater than 90 percent average fill rates and industry-leading eCPM levels across all categories of iPhone app inventory. And we intend to continue to lead the industry by working as closely as possible with our app developer customers.

Ali Diab
VP of Product Management
AdMob