What does this mean for the developer revenue share on premium upgrades. Today an app is incented to provide a link to the Evernote page to upgrade to premium (so the Dev gets a share). It sounds like apple would consider this a link to an external payment service and not allow it. Any plans to let third party apps transact the in app purchase upgrade to premium and take a rev share? I can see this being tricky (I.e. Impossible) as the in app purchase has to be for developer listed skus and not for third party skus (like an Evernote one)... Thoughts on this?