If you're targeting a specific demographic try the following:
Go to a small town, and figure out where they tend to be at various times of day.
Then, return to your target market, and post
- one-sheet ads,
- postcards, or
- business cards
- laundromats (singles),
- libraries (old people),
- parks (stay at home moms),
- and/or other locations (gotta do SOME of the work yourself!)
Also, relentlessly pitch yourself and your idea to everyone you meet. This will help you understand your market better, for free, as well as help you practice facing down much tougher stares from investors, recruits, customers, etc.