How does choice affect donation behavior?

How many times have you seen a donation box like the one below? Pretty standard, right? This is from United Way’s website. I’d like to question whether this is the best way to present a donation request.

The issue I have with this approach is that it turns the donation process into a complex decision. The logic flows like this: (a) ‘should I donate?,’ if yes, then (b) ‘is one of the preset options the right amount?’. If that answer is yes, then (c) ‘which option should I select’, or if no, (d) ‘how much should I give instead?’. So there are at least three points at which the donor is given the chance to exit the decision making process and avoid making a donation altogether. To me, that’s a less than optimal user experience.

Now, here’s something from the other extreme:

Granted, this is from Amazon, not a charity. But it provides the easiest possible way to complete a transaction – one click. This is literally the simplest user experience a site could offer.

I have to caveat this by saying that I haven’t seen “one-click” giving implemented anywhere. But what if it were? There would be no complexity: as long as the suggested donation was within a potential donor’s reach, all he would have to do is click a button. It’s a binary decision (yes/no) instead of a complex one. While this approach might put a cap on the amount of a single donation, might that be offset by driving a higher quantity of donations?

I don’t have the answer, since I don’t have any data to go on. But I’d really like to see someone experiment with “one-click giving”. Do you know anyone who has?