Amazon has rolled out its equivalent of PayPal and Google Checkout in two flavors: Checkout by Amazon and Amazon Simple Pay. Both services fall under the Amazon Payments banner and allow third party retailers to access Amazon user accounts for payment.

The service integrates with Amazon Marketplace as well as third party sites. A "Checkout with Amazon" button takes the user to the Amazon Payments site where they sign into their account and pay for shipping.

Checkout by Amazon offers retailers all of Amazon's bells and whistles, including one click and "express lane" payment, as well as the recently unveiled Bill Me Later deferred payment option. Retailers using Checkout by Amazon also have access to Amazon's pipeline and order management services which include shipping rate and sales tax calculation, buyer feedback collection, and multi-user account access control.

Amazon Simple Pay, meanwhile, strips away many of the additional services and concentrates strictly on payment.

Both options, like eBay, incur a fee on a per-transaction basis with Amazon receiving a percentage of the transaction amount. For transactions greater than or equal to $10, Amazon takes 2.9% plus $0.30. This percentage decreases with the volume of transactions the retailer makes per month. A retailer who has a monthly payment volume of over $100,000 will pay only %1.9 per transaction, for example.

Amazon Payments has grown considerably this year, with the introduction of TextBuyIt and TextPayMe in April, services that allow customers to comparison shop and exchange money via text message.