The simplest checkout
A PayPal button posts the product to PayPal. The customer pays. PayPal pings your server back (IPN):
<?php
// verify the IPN with PayPal
$res = file_get_contents('https://ipnpb.paypal.com/cgi-bin/webscr?cmd=_notify-validate&' . $raw);
if ($res === 'VERIFIED') {
// grant download, create license
}
Why this works
- No monthly fees - PayPal takes ~3% only when you sell
- No PCI compliance headaches - PayPal handles card data
- Works worldwide
Perfect for digital products under $100.