Google has extended the free transactions for merchants till 2008. That is over 1 year of credit card processing for your website FOR FREE!
This is a huge push from Google to get people to switch from their current provided (which typically charges a monthly charge PLUS transaction fee), or from PayPal which charges a higher transaction fee then Google when Google was charging a transaction fee.
This is great for any small business and will certainly add up in the long run for any one selling items online. Easy instructions on how to integrate this into your site can be found here. They’ve also dropped in new features in for merchants, including easy coupon creation, and email invoices.