It’s no secret that the mobile web is exploding. According to IDC, more people in the US are projected to access the web via a mobile device than on a computer by 2015. This makes mobile a very attractive opportunity for advertisers, and is creating a wave of new revenue opportunities for publishers.

In order to bring more mobile inventory to buyers on the DoubleClick Ad Exchange, we’ve launched two important initiatives for the mobile-specific 320×50 ad size.

First, buyers will be able to access AdMob in-app mobile inventory from AdMob publishers and application developers. Last week, we opened access to this inventory to a preselected set of Ad Exchange buyers. Second, as of today, we are beginning to test the ability for Ad Exchange publishers to opt in their 320×50 size mobile web inventory into the Ad Exchange. This will open up new mobile web inventory for Ad Exchange buyers. As publisher participation in these initiatives grows, we expect the inventory pool for in-app and mobile web inventory that’s specific to the 320×50 ad size to expand as well.

With the DoubleClick Ad Exchange, this new mobile inventory can be purchased via RTB or the UI. Ad Exchange buyers who are interested in the new 320×50 ad size should be sure to share their interest with their account manager.