On library fines

I think one of the hardest things about libraries for patrons is late fines. I often have patrons ask if their fines can be "reduced" or "waived." Mostly, unless we determine that the fine was due to an error on the library's part, we don't waive fines. The money from fines pays for library services, and are, in effect, forced donations.

The burden is on the patron to pay attention to their due date and return the material by that day--a simple request, for the most part. And, if they don't, for our system, it's $.20 per day, per item for adult books, $.10 per day, per item for children's books, and $1.00 per item, per day for movies, with a cap at $6.00 per item.

I know there are public libraries that do not charge late fees, but I don't know how the library where I work would manage to function without that revenue. My question is, how would public libraries be able to get materials back on time for other patrons to use them without the negative reinforcement of late fees? What do the libraries that don't charge fines do to encourage patrons to return in-demand material by the due date? What kind of positive reinforcement could be given to patrons who do return items on time?