Hi,

I'm having some trouble choosing between PayPal's Instant Payment Notification (IPN) and Payment Data Transfer (PDT).

Basically, users buy a one-off product on my site, pay on PayPal, and return to my site. I understand how IPN works but I'm now seeing that I might be able to trigger the various actions that take place after a successful purchase more easily with PDT, as the data gets returned there and then (as opposed to needing a separate listener).

However, PayPal's PDT documentation contains this cryptic line: "PDT is not meant to be used with credit card or Express Checkout transactions." ... but I can't find anything further whatsoever on the topic.

(1) Are credit cards REALLY not meant to be used with PDT? I would like more than a sentence.

(2) Does that mean that a user must have/create a PayPal account to pay?

(3) Does it mean that if I want to allow users to pay with their PayPal accounts AND/OR with credit cards directly, I must implement IPN?

Could anyone who's gone through this kindly shed some light?

Thank you.