Great interview with HP cloud leader, Marten Mickos that very simply explains open source and why trying to upsell free users to paying customers doesn’t work.
"You need to come to terms with the idea that some people will spend any amount of time to save money. Other people will spend money to save time. It is that philosophical difference between people that makes the business model. You reach out with the open source software to reach everybody. You reach out with a business model to those who are ready to spend money in order to save time."
via HP's Marten Mickos: Open Source Is Not a Business Model | Exclusives | LinuxInsider.