I know you mentioned not liking Amazon for the sign-up step, but in practice I haven't noticed much of a fall-off because of it. I use Amazon's Flexible Paymen

I know you mentioned not liking Amazon for the sign-up step, but in practice I haven't noticed much of a fall-off because of it. I use Amazon's Flexible Payments Service for taking small payments (<$2), and I've been pretty happy. About 10% of the people who click the "buy it" button on my product get to the Amazon sign-in/registration page and then bail. Abandoned funnels always sting, especially so close to completion, but is a 10% abandonment rate worse than it would be for a more direct credit card payment system? I doubt it, though I admit that I don't have any solid data to support that assertion. Might be worth trying.