McMillan states, "Mozilla wants to introduce a common web API to make payments easy and secure on web devices yet still as flexible as the checkout button for merchants."
Introduced initially in Firefox OS to allow web apps to accept payments. When a web app launches in the OS, the device will show a secure window with a concise UI. This enables users to easily charge the payment to their mobile carrier bill or credit card. The app then delivers the product and repeat purchases are quick and easy.
The multiple payment providers mentioned earlier will for example enable the Firefox Marketplace to facilitate payments.
Mozilla are also working towards enabling paid, ad-free web content. McMillan has stated that although paying for content has been profitable on mobile apps, it hasn't translated to the web.
Mozilla want to enable quick, secure processing for small transactions but as The Verge reports, McMillan has said "the web should support businesses of all kinds and payments should be a first class feature of the web."
The company have said the new API is experimental and could 'change drastically' without notice, but have reported it will ship with the first Firefox OS devices.
Sony announced in February that they would be launching the Firefox OS device in 2014.