Payment providers without sign-up or monthly fee?

only percentage (and/or fixed fee) per payment?

[Platypus]

Hi, are there any payment providers (i.e. organizations through which you can accept and process credit card payments from customers) that charge a per-order fee only?

Most services have one-time setup fees, or fixed monthly fees. But I'm currently in search of one that has NO fixed fees, and only charges per order or payment.

Preferably, I only need a service that processes the payment, i.e. not the logistics / sending the product or license or whatnot.

Any recommendations?

[vincevincevince]

I don't think we can actually name them - but there are quite a few, including some of the biggest names in online payment processing.