Summer reading prize idea

Here's an idea. One Denver area library has, as one of their summer reading prizes for teens, a $2.00 off your fines coupon. Sort of a "get out of jail free" card for the rascals who don't return their books on time. I think it's a great idea especially since it pretty much costs the library nothing. (Chances are they wouldn't get most of that money back anyway and many of the participants will never have the need to use it.) I hear though that it took a lot of work to convince management of the idea.