From reading the app store review guidelines and had a look of several well known apps like NY Times, WSJ and Time magazine, it's quite clear that providing digital content consumable within the app requires the use of In-app Purchase as payment method. However I came across an eboook app recently that provides In-app Purchase for subscription as well as single ebook purchase with payment methods like credit card, Alipay and Paypal. The app has been on the store for over a year. I would like to ask if:
(1) the requirements were changed to be more lenient towards providing payment options,
(2) Apple actually allows to provide other payment options if In-app Purchase is provided as well, or
(3) just a case which Apple didn't find out the app provides other payment options
Cheers!