New to iOS 6 is the ability to “limit” Apple’s ability to track your phone usage statistics for advertising. To limit Apple’s tracking of your device, navigate to Settings > General > About > Advertising and toggle the switch to “On”. Tapping “Learn More” at the bottom of the last screen brings up the following:
iOS 6 introduces the Advertising Identifier, a non-permanent, non-personal, device identifier, that apps will use to give you more control over advertiser’s ability to use tracking methods. If you choose to limit ad tracking, apps are not permitted to use the Advertising Identifier to serve you targeted ads. In the future all apps will be required to use the Advertising Identifier. However, until then, you may still receive targeted ads.
It appears as though Apple has plans to completely control how ads are transmitted to iPhone owners in the future and opting out of the ad tracking at this point should significantly lower the amount of targeted ads you receive.