Amazon’s Flexible Payments Service to compete with Google Checkout, PayPal
:

A new payment service for online vendors has entered the scene, this time
introduced by online retail giant Amazon. The Amazon
Flexible Payments Service offers an extensive API to developers that will
allow them to process payments on their own websites, which can be easily
scaled up or down to handle whatever traffic volume is needed. If successful,
Amazon FPS will compete with other similar services such as Authorize.net,
PayPal, and Google
Checkout.

Good price points, worth looking at deeper (micro payments are almost realistic with this…)