iAd-supported versions of apps targeted at kids may soon disappear from the App Store, thanks to an apparent change in Apple's iAd policy. The change came to light after developer Mike Zornek noticed that his Pokémon browsing app, Dex, was pulling in an unusually low number of iAds. When he asked Apple about what was going on, the company told him that its advertisers prefer not to advertise in apps targeted at "young children," thereby killing the iAd-supported version of Dex.

"We periodically review the apps in the iAd Network to ensure that all apps receiving ads are aligned with the needs of our advertisers. Currently, our advertisers prefer that their advertising not appear in applications that are targeted for users that are young children, since their products are not targeted at that audience," iAd Network Support told Zornek via e-mail. "We appreciate your understanding."

It's hard to argue with that reasoning, and it sounds like the advertisers are ultimately the ones who are calling the shots. Still, the way in which Apple notified Zornek of the change leaves a lot to be desired—Apple wasn't proactive in notifying Zornek (or presumably any other developers who offer kid-focused apps), and nearly a week went by before he got any kind of response to his inquiry.

Zornek also points out that there has been no change in iAd documentation or to the iAd developer page, potentially misleading current and future developers who might try to offer ad-supported children's games. "No warning, no notice and inevitably no respect to the developers who have centered their app’s revenue model around the iAd platform," Zornek wrote. "Today was another harsh reminder we iPhone developers are making a living at the beck and whim of a powerful platform vender. Be careful putting all your eggs in his basket."

It's possible that Apple hasn't changed its documentation because it's not a permanent policy—advertisers can be fickle, and they may suddenly be inspired to advertise in kid-targeted apps again sometime in the future. Apple did not respond to our requests for comment by publication time, however, so for now, it looks like affected developers will have to either ditch iAd for something like AdMob or stick to developing paid apps for kids.