An obvious promise of mobile ads is that they can be location-aware; products can be pitched to people based on where they are. But Apple (NSDQ: AAPL) may have just limited that on the iPhone. In a short post on the iPhone developer blog, the company warns developers that if their app uses location-based information, that information must be put to “beneficial” use: “If your app uses location-based information primarily to enable mobile advertisers to deliver targeted ads based on a user’s location, your app will be returned to you by the App Store Review Team for modification before it can be posted to the App Store.”