CodeCanyon - PayPal File Download v2.0.1 WordPress Plugin | 308 KB
PayPal File Download for WordPress is the easiest way to sell digital content. Easily sell and automatically deliver e-books, PDFs, ZIPs, and any other kind of file to your customers-with built in IPN , email delivery, and download expiry.
Integrating directly with PayPal Website Payments Standard with a built-in seamless IPN system, your users will be able to hit Buy Now, check out, and instantly have your digital goods delivered to their email inbox in seconds.
DEMO:
http://codecanyon.net/item/paypal-file-download-wordpress-plugin/115231