Hi SteveD,
Have you considered an advert on facebook? Quite cheap for the amount of people you can reach.
You are also able to target specific groups, demographics etc.
You can also set daily budgets on costs etc, so it never blows out.
You could also branch out into cd's etc..then you could add a cleaning and restoration service, commercial disc cleaners are fairly cheap now and individual disc cleaning / restoration (remove scratches etc) only costs you around .19c per disc.
Just some ideas
Cheers.