Facebook oauth 2.0 invite friends feature

Question

I'm planning go implement the new oauth 2 login which will give me app scoped facebook ids instead of the real facebook user id. My question is how to implement invite friends feature which will reward the users which invited friends (after the friends join my site). With the old oauth 1 I would store the invitor id and invited id and when the invited user joins - I simply reward the user who invited him..but with the new auth I can't compare friend ID to app scoped user id.

Any suggestions how can I do this ?

Answer 1

Don't incentivise people to invite their friends, unfortunately it's against Facebook's policies (4.5):

Only incentivize a person to log into your app, like your app’s Page, enter a promotion on your app’s Page, or check-in at a place. Don’t incentivize other actions. (Effective November 5th, 2014, you may no longer incentivize people to like your app's Page).