在Temple Run SIAP 商店里,如果你喜欢他们的Facebook页面,他们免费给你250个硬币。 (实际上,他们只是把你转到他们的Facebook页面上)
I would like to do something similiar for my app. The problem is that the user should be able to do this ONLY once. (Just like a non-consumable iap content) I cannot save it in the app configs either, because the user can delete and redownload the app and the free content would up show again.
这样做的最佳方法是什么?