At WWDC, Apple changed the wording on iPhone developer program agreement, that "essentially locks out companies that gather usage data from the platform. The new agreement states that user data may only be transmitted by "an independent advertising service provider, whose primary business is serving mobile ads" and they must not be a "developer or distributer of mobile devices, mobile operating systems or development environments other than Apple". This explicitly excludes Google - due to Android OS, and Adobe, due to it's Flash platform."
Reuters reports "AdMob disclosed that 1/3 of all ads served through their network are served on iPhone platform. The new agreement would be a large hit to the company if they could not advertise anymore, and both iPhone and iPad are affected."
Omar Hamoui, said that "this change isn't in the best interests of users or developers" and that "artificial barriers to competition hurts users and developers and in the long run, stalls technological progress". He went on to say that Google will be raising its concerns with new rules with Apple.