During the Q4 2010 conference call, Apple stated that their acquisition of Quattro Wireless would allow them to provide a "seamless" mobile advertising option for iPhone and iPod touch (and presumably iTablet?) developers, especially developers of free apps.

Mobile advertising is only going to become more important as a revenue stream, and with Google swooping in and snatching up AdMob, Apple is likely going to leverage their development environment and talent at integration to make their alternative as competitive as possible.

Developers get easy ads and a additional way to make money, Apple gets an additional revenue stream and the valuable metrics that go with it, and end users get free or cheaper apps but have to put up with some advertising.