Authorize.net (www.fourhourblog.com/authorize) The Authorize.Net Payment Gateway can help you accept credit card and electronic check payments quickly and affordably. More than 230,000 merchants trust Authorize.net to manage their transactions, help prevent fraud, and grow their business. The fees per transaction are lower than PayPal or Google Checkout, but setup will require a merchant account, covered in the next chapter, and other time-consuming applications. I suggest setting up Authorize.net only after a product has tested successfully through one of the other two options above.