If there's one questionable practice employed by SM and Content Paradise, it's that they include Download Protection by default on their invoices. It's up to you to remove it before submitting the order, which is not really kosher in most people's eyes. Many folks just trust that the invoice is OK and click through.

Anyway, just remove that $1.68 item and proceed with the order. Then you won't need your credit card because there's no charge.