Amazon FPS (Flexible Payments Service) is an Amazon Web Service that allows the transfer of money between two entities. The service was launched as a limited beta in August 2007, and later in February 2009 was promoted to General Availability. Some of the features of Amazon FPS are:
Support for micropayments by grouping several small transactions into a larger one paid for by traditional e-commerce means.
Ability to pay by credit card, bank account, and Amazon Payments account balances.
Programmatically define payment instructions on each transaction.
Support for multiple, recurring and three-party marketplace payments.
Amazon Simple Pay : It is a set of basic payment-only products. Using online Amazon Simple Pay forms merchants can create fully functional payment buttons, which they then add to their web pages. When customers click one of these buttons, they begin making a secure payment.