Facebook - ways to notify non app users

Is there any other way expect "requests 2.0" https://developers.facebook.com/docs/reference/dialogs/requests/ to send short message to non 开发者_开发百科app users ?

The only other option is to let uses send messages with the Send Button. However, this does not provide any feedback to you the way app requests do: the best you can typically do is put in a link and check to see if it gets clicked by the recipient. But otherwise no, currently apprequests are the only way to send messages.

The only other way is to write on friends walls - but that is a way to get your app marked as spam if you aren't very careful with it. The requests dialog doesn't have an API, Facebook won't give you a friends email address, and it won't let you send Facebook messages to friends any more via the api.