Since launching Etelos CRM for Google Apps -- a lightweight CRM app that works with Google's productivity suite -- on Feb. 28, Etelos has nearly 3,000 businesses representing 30,000 individuals using the product, Etelos CEO Danny Kolke said at Interop today.

That's an impressive number, and it's one that clearly validates the desire among businesses (I suspect mostly small businesses) for lighter weight, lower cost apps without lots of hosting and maintenance challenges. The numbers give even more momentum to the software as a service movement. A professional edition of the software costs $12 per user per month.

At the same time, 800 developers have signed up for a CRM for Google Apps developer program, Kolke says. Planned additions from those third parties span everything from a VOIP module to vertical industry-specific functions such as those for financial services.