Integrating Gravity Forms with Shopp plugin

I didnt get a reply from the Shopp guys however i've tested the following script and it seems to work ok. Can you see any obvious problems with it?

$url = "__WORDPRESS PAGE/POST URL__";

$post_data = array (
	"is_submit_1" => "1",
	"input_X" => "name",
	"input_X" => "email@email.com"
);

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $url);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
// we are doing a POST request
curl_setopt($ch, CURLOPT_POST, 1);
// adding the post variables to the request
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);

$output = curl_exec($ch);

curl_close($ch);

I found that the URL had to be different from the ones that calls it but this isnt a problem for my situation.
In the real situation, I would replace the post_data object with the values submitted on the checkout process.

Could you describe what you're doing here in more detail? I'm interested in doing the exact same thing, but unsure what to do with the script mentioned above. Thank you.