@chessknight
Does this now mean we are not allowed to use Paypal anymore for tips? "May" makes it sound like you can use IAP but do not have to.... my app just got rejected with following reason:
"Although tips or donations may be optional, if they are connected to or associated with receiving digital content, they must use in-app purchase in accordance with guideline 3.1.1"
Reading their quote my app should fall into the exception since the user does not get any additional content...