A great way to get some cheap advertisement for your game out there, is to go out and buy a nice, large bell. The initial investment might set you back about $20, but it will keep you out of having to deal with any pesky companies.
So the general concept, is to dress up in some clothing that will stand out in a crowd. Then you would ring your bell and yell "Hear Ye! Hear Ye!" to gather up a crowd around you. Once you get people's attention, you can then talk about your game.
Try to be concise when you detail your game, as you don't want to bore people. And remember to smile.
It is also a great idea to have hand-out material ready for people to pick up so that they can take that information with them.