1) Bezos said: "Percentage margins are not one of the things we are seeking to optimize. It's the absolute dollar-free cash flow per share that you want to maximize, and if you can do that by lowering margins, we would do that. So if you could take the free cash flow, that's something that investors can spend. Investors can't spend percentage margins" (http://blogs.hbr.org/ideacast/2013/01/jeff-bezos-on-leading-...)
2) Listen to Ruby on Rails' DHH break it all down here @ 44min30sec (he also knocks salesforce) quoting Bezos' line "your margin is my opportunity": http://www.youtube.com/watch?v=jzERXJgi5vQ&t=44m30s
"And the reason that I'm doing this interview with you is I want customers to understand what makes us tick, how we operate, what our principles are. I think customers want to know who they're doing business with."
smart!