There are many online tools that are free. For example Skype and Prezi. Have you ever thought how they make money? It is very easy, they have some basic free services and some upgraded paid services. Therefore, everybody wins. Customers that just need some basic tools, the business itself and of course paying customers since they are willing to pay for a better service.

From my point of view, this is one of the best innovations of the century. PPC and advertising revenues model are too simple and do not offer that much value to businesses and customers. But this is just and opinion, what do you think?

http://smallbiztrends.com/2009/04/skype-free-business-model-drives-revenue.html