Open Source bussines model: a proof of concept

I was reading this interview with David Wheeler, Bricolage author and I realize this is a proof of concept about Open Source bussines model. He had wrote a CMS and you will use it for free and if you want something more they offer you a comercial support (really cheap in my opinion). There's a lot of prominent customers, this list talk us about how good product is.

Although it may seems publicity, in fact is just jealousy, 'cause I had to be great way of living developed something and live doing something that like ... yes, yes, I know there's always the other side of story not said here, nasty customers, bills to be paid, ...