A VIP contest is another good way if we are talking kids. Have every kid hand out "FREE VIP" cards to at least 5 friends. The pass gives a free uniform and a free month of classes. There are ways to convert these students into full students, BTW. For every student that has a response they earn say, 5 tickets. For every contact of theirs that joins they earn an additional 10 tickets. After the length of the contest, say 3 months, you have a VIP Party for all those with tickets. The tickets are drawn for door prizes such as gift certificates to your pro shop, restaurant gift cards, whatever. There is one grand prize, like a new bike, a Nintendo Wii, or something worthwhile to get the kids excited.
With respect,
Mitch Saret