Freebie: Instant checkout script - Use your OWN landing pages to sell the product

If you were wondering, like me, how to let your visitors buy Amazon products directly, without seeing the product page first, here's the solution.
Create your own landing page for a certain product and let your visitors go to Amazon checkout directly to purchase it.

This is what it looks like:


To do this, save the following code as checkout.php and create a link to checkout.php?i=ASIN_HERE.

<?php
//Amazon Easy Checkout
//Copyright (C) 2006 Daniel "DXL" de Leeuw.
//If you like/use this script, please consider making a donation to danieldl@gmail.com with PayPal.

//Configuration === Edit this!
$access_key = 'XXXXXXXXXXXXXXXXX';
$associate_tag = 'XXXXXXXXXXXX-20';

//Basics
$base_url = 'http://webservices.amazon.com/onca/xml?Service=AWSECommerceService&AWSAccessKeyId='.$access_key.'&AssociateTag='.$associate_tag;
preg_match('/([A-Z0-9]+)/i', $_GET['i'], $matches);
$asin = $matches[1];

//Cart Creation
$creation = httpget($base_url.'&Operation=CartCreate&Item.1.ASIN='.$asin.'&Item.1.Quantity=1');
preg_match('/<PurchaseURL>([^<]+)<\/PurchaseURL>/', $creation, $matches);
if($matches[1])
    header('Location: '.$matches[1]);
else
    print 'Sorry, an error occured. Your request could not be fulfilled.';

//Functions
function httpget($url) {
    return implode("\n", file($url));
}
?>

PHP:

If you like this, please give me some green rep or $1 (I'm at PayPal).

~DXL

P.S. Of course feel free to redistribute, providing proper attribution.