"[...]Visitors will leave at the slightest obstacle. So if you want people to visit and order from your site, don't put any obstacles in their way. Whatever yo

"[...]Visitors will leave at the slightest obstacle. So if you want people to visit and order from your site, don't put any obstacles in their way. Whatever you do, don't force visitors to register."-Paul Graham, "The 10 Secrets of Selling Online: #4. Make Your Site Easy," http://store.yahoo.com/easy.html http://store.yahoo.com/easy.html By accepting only Google Checkout, you are adding an obstacle to everyone who does not already have a Google Checkout account, and thus discouraging casual browsers from executing a purchase. I'd personally encounter a lot less "mental friction" logging into an existing Paypal account or the like and pressing a few buttons than going to another site, starting creating an account, finding and typing in a credit-card number, enter an address, glance through the Terms of Service, etc... Of course, depending on your product, there may not be such thing as a "casual browser" who may leave and look at a similar product merely based on the inconvenience of making an account, but it is nevertheless a large obstacle; it's just that the seeker and prize on either side have suddenly increased in strength.