I have a private, paid-user-only service and I'm using Paypal Subscriptions as my payment gateway. It has been properly set-up (or I believe it has) with custom URLs defined for successful payments or cancellations.
The success URL is what "activates" the user's account. However I find that users who make the payment don't follow thru by continuing to the successful payment URL. For users who cancel, I don't have a problem.
But for those who make the payment but will not follow thru, I end up having to manually activate their accounts.
What I need is Paypal to "ping" my activation / success URL when the payment is complete. I'm sure I've seen websites do this properly with Paypal. I wonder how it is done.