There seems to be a misunderstanding. I wasn't talking about software as a service, I was talking about service around software (e.g. guarantee that it works, provide a hotline for all kinds of issues, which might include fixing bugs etc).

In constrast, SaaS is usually quite the contrary of Open Source. You do not only pay per license, but for usage time and/or the amount of data. You don't see the source, you can't make any modification, you don't have any direct access to the machine, and you are (usually) stuck to a single vendor. All of this could be fixed, of course, but as of now, the economy model around SaaS is more an aggravation of the proprietary model, and nowhere similar to Open Source business models.