See:
How do agents get leads for Medicare Supplements? What is the best source for Medigap leads for agents?
Many of our members use varying methods with success, including: direct mail, cold calling, door knocking, Facebook, Google Adwords, Youtube, etc.
They all work. I have found that agents, though, seem to find what they are most comfortable working with, and sometimes that changes in their business cycle.
https://www.youtube.com/watch?v=XZRw6JaZXYE