If you haven't already, I can recommend reading the book Traction - http://tractionbook.com http://tractionbook.com Gabriel and Justin have done a good job of

If you haven't already, I can recommend reading the book Traction - http://tractionbook.com http://tractionbook.com Gabriel and Justin have done a good job of not just identifying marketing channels loaded with successful case studies, but providing the business framework for testing them on an ongoing basis to keep "moving the needle".