You should design experiences into your app to allow users to send requests to friend to drive re-engagement. Some design experiences include giving users the ability to request gifts, accept gifts, or help them complete a mission in your app. For example in Diamond Dash you can send a life to a friend. If that friend has not been using the app for a while this could help re-engage them.
Another design experience to consider is to allow users invite their friends to use your app. For example, there are apps that ask users to rate the app after some time. If you wanted to build something similar to drive engagement you could ask users to invite their friends. Wherever you have a button or call to action to rate the app, think about adding a flow to invite friends.
These user-generated requests are initiated when the app enables the user to select one or more friends to send a request to.
We will walk you through the steps to send out an invite or a request:
Triggering when the invitation or request is sent
Sending the request
Sending additional data with the request, such as a virtual gift
このチュートリアルを参照してください: http://developers.facebook.com/docs/howtos/send-requests-using-ios-sdk/
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