updated 04:45 pm EDT, Fri March 22, 2013
May be in response to string of child spending sprees
Apple has added an "Offers In-App Purchases" tag to the pages for applicable App Store titles, The Guardian observes. The warning is directly under the purchase/download button for any given app. There was already some indication of whether or not a title had in-app purchases, but only in the form of a "Top In-App Purchases" chart or a direct statement by a developer.
The change may be in response to a continuing string of spending sprees by children. A growing number of games are free to download but in reality make their money off purchases for in-app items and currency; in some cases, it may not be clear to children or parents that the purchases will cost real money. The Guardian cautions that this week's change might not make much difference, since the warning only appears in the desktop version of the App Store and not the mobile one, where most app downloads are made.