Apple has begun rejecting apps which ask for an IDFA (Identifier for Advertiser) but don't actually display ads. IDFAs are used by apps which display ads to count the number of unique people opening it, and then developers can charge advertisers a price based on the number of IDFAs they have collected. The more IDFAs attached to an app, the higher the advertising price.
Apparently though, some developers have been using IDFAs for reasons other than advertising. Inflating the number of IFDAs collected to charge a higher price or simply for tracking users to see what is popular. These practices go against a clause in Apple's developer license which states that asking for an IDFA must be used for advertisements only.
You and Your Applications (and any third party with whom you have contracted to serve advertising) may use the Advertising Identifier, and any information obtained through the use of the Advertising Identifier, only for the purpose of serving advertising. If a user resets the Advertising Identifier, then You agree not to combine, correlate, link or otherwise associate, either directly or indirectly, the prior Advertising Identifier and any derived information with the reset Advertising Identifier.
Tapstream believes that this rule is now being enforced to boost the iAd network and force a switch over to a "click" service, which ultimately harms advertisers.
As a side effect, this will push ad networks to a Cost Per Click (CPC) model and away from CPI – which is worse for the advertisers. (Publishers generally already get paid per click, ahem tap, or impression). Of course, it helps that Apple's own ad network, iAd, is not affected by these restrictions. Advertisers who want to preserve their ability to run CPI campaigns may try to work around the new restrictions by adding a small amount of advertising to their app, but whether this will mollify Apple is unclear.
There is a lot of joy in the truths behind advertising dollars. Could be true that Apple is playing a game to put itself on top, or it could just be Apple sticking to its own rules written in its own license. You decide. Apple has also yet to comment on the app rejections.