Google warned about Apple's decision to prohibit some ad networks and ad data on its products, including iPod Touch, iPhone, and iPad, according to news reports on Friday. As quoted by Reuters, Apple's revised term and conditions stated ad collection is banned "unless it is provided to an independent advertising service provider whose primary business is serving mobile ads."

It indicates it would ban Google's ad company AdMob, which Google acquired in May for 750 million U.S. dollars. AdMob's founder Omar Hamoui said in a blog post that the change is not in the interests of customers, "Artificial barriers to competition hurt users and developers and, in the long run, stall technological progress."

"It looks like Apple is choosing to exclude its biggest competitor from the iPhone," said Karsten Weide of IDC, "That mans more revenue for Apple in the short term, since ads would flow through its system rather than through Google's." On Monday, when Apple launched the iPhone 4, its CEO Steve Jobs aggressively praised Apple's own mobile ad platform that he acclaimed would gain 48 percent of the market by the latter half of 2010.