I used it for years. I had a "shop" page where each button went directly to the payment provider (with the appropriate details). This was the most basic way to make purchases years ago. The payment providers used this method in its examples. You still come across sites doing it this way, here and there.

The patent is beyond ridiculous. I doubt it would hold outside the US. (I'm not in the US, but I use some US-based service providers.) But I guess someone, sometime will have to go through the process of knocking this patent down, such is the madness that the patent process has become.

Barnes & Noble tested this 10 years ago and their solution was to add a second "confirmation" click. That would seem to be about the minimum necessary to avoid infringement.

Apple iTunes credits Amazon in their patent credits section: http://grab.by/7RGo

I spent a few days earlier this week adding hoops to a checkout process to avoid infringing on this. Previous devs had naively implemented something they thought made sense & made things easier for the customer. Foolish fools!

Still makes me angry that they got away with this.

You can implement it, but you're inviting patent litigation.