Windows Phone Mango will not support in-app purchases
There were rumors and hopes that in-app purchases would be coming to Windows Phone Mango this fall, but that hope has been smashed. There were never any definitive rumors to cling to, but in-app purchases have become something of a standard on other mobile platforms, so the hope was always there. Unfortunately, word straight from Microsoft is saying that although it was a priority, the feature will not be in Mango.
The best we had before was extrapolating from a panel at Microsoft's Gamefest that focused on "downloadable content and microtransactions", but it looks like those features won't be hitting Windows Phone with this next update. In the comments of the Windows Phone Developers Blog post about the recent App Hub update, Microsoft employee Todd Brix put the rumors to rest. Brix said that in-app purchases was a feature that was a high priority for the Mango update, but it "didn't make the cut."
For developers, this is one fewer opportunity to make money from users, but for users this delays the inevitable surge of microtransactions that will come from in-app purchases.
source: Windows Phone Developers Blog via WPCentral
Things that are NOT allowed: