Google's Checkout lets online shoppers store credit card and address information with Google so that they don't have to re-enter the same information each time they buy an item from a different Web site. At the time of launching its service, in late June, Google took care to insist that the offering would not compete with PayPal, the online buying service that is owned by eBay.

Analysts say that even if the current Google Checkout service doesn't exactly compete head on with PayPal, it could in the future. They expect Google to become increasingly active in e-commerce in the longer term and Google could easily boost the Checkout service to offer more capabilities making it similar to PayPal.

The eBay Web page that describes its acceptable payment policy it says that when new payment services arise, eBay will evaluate them to decide if they're appropriate. Some payment services may not be permitted on eBay although they may be appropriate services for consumers in other contexts, the page says.