If you have stickers for your band (and you definitely should), many of your fans will stick them on the back windows of your vehicle. While this isn't the most powerful form of advertising, I do think it helps cement that particular fan's allegiance to you. Vehicles are very personal possessions, and the act of putting a sticker on their car is one of the things that differentiates a normal fan from a 'great' fan.

Why not reward them for it?

1. Print little fliers that thank the fan for their support
2. Carry a pen or a Sharpie with you at all times
3. When you see a car with your sticker on it, sign the flier and stick it under the car's windshield wiper

A little reward for one of your better fans. If it's just a little flier thanking them for their support, you essentially just gave them your autograph. You could take it a step further by making the note worth something:

• Exclusive demo CD for free at a show
• Refund on all or part of the admission to a show
• Discount on apparel, CDs, and other merchandise
• Entrance to backstage to meet the band

As I've said before, you want to turn your normal fans into an unofficial street team. Rewarding behavior that promotes your band ensures that people continue to do it. This will work even better if you don't tell people that you're doing it. Let your fans buy your stickers (or give them away for free) and reward people for advertising for you.