I contrate most advertising to busineses that I frequent via give aways (sport magnets, note pads etc), post cards with recipies on them. The magnets so far are the best. People expect them now so when they show up late, they call me. I can wait and order them for a discount and blame the printer.
Sports sponsorship- I found its better to sponsor a kids team. You gotta print your own banner and hang it up your self and take it down your self but the parents will talk to the sponsers, and its alot cheaper. I'll schedule with the coaches to supply the snacks for both teams on certain games for the kids.
Facebook- I do updates just enough to make my friends remember that I am a Realtor, but I don't annoy people. When I see somebody may need my services I send them a PM, a very informal PM offering my services.