The idea is pretty simple: People will make more purchases if they can easily check out. PayPal has introduced the concept of a digital wallet, with all your payment options behind a single service. Amazon followed this step with its own checkout button. Really, it was only a matter of time before the traditional credit card companies came along. But it's unclear when we'll see their unified checkout button. Bloomberg says Visa and Mastercard still have not discussed offering with retailers, and they hope to work with the World Wide Web Consortium, which sets standards for browsers.
In addition to faster, the new checkout button should be safer. It uses the token technology that Visa and Mastercard rely on and creates a temporary digital ID for each purchase, rather than using your actual card number. This should reduce fraud and make it easier to keep your payment information up-to-date with online services (since the tokens will be updated when you receive new cards).