Q:

Choosing Paypal APIs

I am developing a site in PHP with premium features for a fee. A premium user can choose to pay every mont, every 3 months or every year.
The Paypal docs say that the Merchant APIs include Express Checkout, Website Payments Pro, Button Manager, Mass Pay, Recurring Payments, and all of the Informational APIs. And the Adaptive APIs include Adaptive Payments, Adaptive Accounts, the Invoicing Service, and the Permissions Service. Then there are the REST APIs. Then here are the "Subcriptions".
I am not sure which APIs I should choose. Seems that in my case the Recurring Payments are managed only by the Merchant APIs, is that correct? Any advantage if using "Subcriptions" instead of  Recurring Payments?

A:

I would recommend going with Express Checkout which allows you to setup "recurring payments".  Recurring payment's are essentially the same thing that "subscriptions" are, but they give you a little more freedom to work with because it's all API based instead of setup using standard HTML buttons.
Later, if you want to add the ability for enter credit card details directly on the site instead of redirecting through PayPal you can add the Pro piece very easily.
If you're using PHP, my class library for PayPal will make all of this very simple for you and comes with fully functional samples.

