Recurring Payments with Digital Goods for Express Checkout is the verbose name PayPal chose for their most convenient subscription service.
If you’ve spent more than a few minutes in the PayPal documentation, you will know it’s easier to manually decrypt a 1024 bit RSA private key than to understand the PayPal Digital Goods with Express Checkout API.
After I put in the human computing cycles to decrypt the documentation & API, I funnelled the knowledge into an easy-to-use PHP library. I am now in the process of publishing human friendly documentation on how to use this library (and the Digital Goods product) on this site.
Digital Goods Basics
If you are not familiar with PayPal’s Digital Goods product, have a quick read of the introduction page. As the name suggests, it’s a payment solution for non-physical goods.
The Digital Goods killer feature is in-context payments. This new process prevents purchasers venturing too far from your website to make the payment, which promises to lower checkout abandonment rates.
This site assumes a knowledge of the PayPal Digital Goods for Express Checkout product and its incontext payment process. A working knowledge of PHP and object oriented PHP development is also required to understand how to use the library.