Amazon has launched a new feature that will allow members to use their login credentials at other third-party retailers. Aptly named Login and Pay with Amazon, the service is expected to immediately compete with credit cards and PayPal as payment methods for online shoppers.

Specifically, Amazon made available a set of APIs and widgets that merchants can install on their checkout pages. For consumers, this means they will be able to pay for purchases from sites not named Amazon using their Amazon shipping and billing data. What's more, all purchases made through the system will be covered under Amazon's purchase guarantees just like if they were shopping with the e-retailer.

Merchants will benefit from Amazon fraud protection and will pay 2.9 percent plus a $0.30 fee (or less) per transaction which puts it in line with similar offerings from PayPal.

Tom Taylor, Vice President, Amazon Payments, noted in a press release that the company now has more than 215 million active user accounts and with the new system, they won't be sharing any credit card data with third-party sites. The site is second only to Apple with regard to the number of active credit cards on file. Cupertino had more than 575 million accounts on file at last check.

The feature is said to work in desktop mode as well as across mobile devices. Those interested in adding the Login and Pay with Amazon feature to their checkout can do so by visiting Amazon Payments.