Stickers are a great way for any small business to market itself in a very affordable way.  They keep your business in potential clients minds.  Every time they see the sticker with your logo, it hammers your business in to their mind.  Restaurants are a great example of this.  When asked, "What's for lunch?" someone may immediately remember the sticker they saw while driving to work that morning.  There are numerous ways to use them, but here a few to get you started.

Bumper Stickers
Bumper stickers are on of the easiest ways to get mobile marketing.  Almost everyone drives to and from where they need to go.  When they get behind a car with one of your stickers, they'll most likely notice it and the more often they see this sticker, the more likely they are to call you when they need your service or product.
Kids Love Stickers
Give them to kids.  They'll stick them on their notebooks, in their rooms, on their skateboards, in their lockers, everywhere they can get away with it.  If it is a cool sticker, don't be surprised when people show up to buy some of your stickers.  This is a great way to get your business name out.  And remember the kids of today are the adults of next decade.

Sponsor Something
I'm sure your town has events such as carnivals, concerts, sports tournaments.  Consider sponsoring one of them.  You'll probably have to make some sort of donation, but it will give you the opportunity to hand out your stickers to everyone attending.  This is a good chance to get your sticker in someone's hand and possibly explain your product or service to them.

Direct Mail
Another way for small business's to achieve success is through direct mail.  Add stickers to the mix and people will be more likely to open your envelope or read your postcard.  Everyone loves something free even if it is just a sticker.

Stickers should be clever, eye-catching, bright, attractive, and just plain cool.  They should be something that the people want to stick.  Nothing offensive.  Once they make the stick, that sticker will have served it's purpose and market your business to everyone that see it.