Re: Open house?
A public demonstration in some place like a shopping mall can be very compelling. Just have flyers or business cards on a table, and have the instructors and seniors hang around between demo sessions to answer questions. Many malls will let you do this, provided you don't put spectators on the mat, and sign a waiver for your own people. Big flea markets and county fairs are also a possibility. A website is also a good thing to have.