So far I have not talked with any dentists who can definitely say that their investment in Social Media has paid off. According to the Mashable article linked below they are not alone. Most businesses getting into social media seem to be doing it on faith.That is it seems like the cool kid thing to be doing and it looks like it will pay off and …well I think it will pay off. The linked article has some good advice on what to measure and how to measure it to determine your ROI.
The key point is that all of your social media programs –- Facebook, Twitter, YouTube, etc. –- should drive people to the landing page on your website where you can convert them from tire kickers prospects to paying customers.
Another excellent source on social media for dentists is Jason Lipscomb and Social Media for Dentists.