Amazon - thats easy, all of them. As long as you are paying he will find a way of taking them.
I think eBay/Paypal was a missed opportunity. They were really the first into this gap (cross planet currency) but were never bold enough to go hard at making it $PP which they could have done.
Often the way with crazy tech startups. You have an idea and build a successful company but you don't develop it out or add another ground breaker. Cisco have done it through buying other new startups which is the other way I guess.
