Health insurance exchanges have nothing to do with Medicare. If you plan things the right way and make a serendipitous move into selling Medicare supplements, your agency is going to grow rapidly. It is a captive market. There is no other term for it. Older Americans are preparing in advance to obtain Medicare, or need Medicare supplements to close any gaps they may have in coverage. Either way, you are offering them something they need, when they need it.
Once you have a Medicare supplement customer, they will typically stay with you for long periods of time, provided you offer them the best of customer service, answer their questions to the best of your ability, help them with claims and make suggestions that would help them save money. Medicare supplement leads are the road to success for an insurance agency because everyone either needs it soon or they need it now. The ball is in your court to make the most of the market.