[ams6110]

Agreed, it seems quite obvious even if there was no prior art (which I doubt, even in 1997, and security issues aside, sites using PHP or ASP or Perl could have been storing credit card data for express checkout functionality).

I also don't see the huge advantage of this. I never use one-click checkout on Amazon. I like to review everything before I buy.

I guess for totally impulse purchases it helps eliminate a step at which the buyer might reconsider a purchase. But I don't like to shop that way.

[Grue3]

>I guess for totally impulse purchases it helps eliminate a step for the buyer to reconsider a purchase.

AFAIK (I only ever used one-click checkout on amazon.co.jp) there's a 15-minute or so window where you can review and modify/cancel your order, so the step is still there (though most people would probably ignore it). I found it convenient to use because domestic shipping was free, and I'm already seeing the price of the product, which is the only thing I'm buying, so there's nothing else to review.

[kbutler]

As liron said, one-click is optimizing the user flow, but allowing easy undo.

It is good UI design:

Optimize the common flow (buy the item) and provide easy undo (from the post-purchase confirmation page, and in the delay before shipping).

But I've still only used it a couple of times - the psychological barrier, wanting to include an add-on item, etc.

[Liron]

You can review everything on the receipt screen and easily undo if you don't like it. This is the same UX as discarding a draft in Gmail - it's done, but you can undo.