One thing I've seen which has consistently worked to bring at least a couple of students now and again is getting into the local rec department / community center. Set up a class through them, usually a couple of months, and usually less than regular rates. It should get a few people in the door.
On demos, we just did one at the local fair with 1000's of people in attendance. We, however, wind up in some off the beaten path section. I think 4 people saw our demo, one of which was my father, and one of the others turned to be Clint George's mother. They've sure never seen Aikido before.
I'm expecting a booming rise in enrollment after that one.
By the way, if you ever do a fair, have puppets or children around. The puppet show had a couple of hundred people watching it. The children's gymnastic's program which went right before us, on our mats, also rocked.