I know that this seems like a good idea in theory, but what you are
doing is devaluing your product. People don't mind paying for cds if
they like the music. you might think about getting some CDR duplication
services for a 3 song promo cd to get it "out there" and then selling
your full cd at current market rate. also allowing people to download
songs first will get some interest in buying your cd. People are used
to getting what they paid for, so from your cd, well, they will expect
nothing if it is free. You could do some online give aways, or make
people think they are getting a free cd that normally cost x amount of
dollars and would likely gain more fans for the fact that they think
they "won" something.

good luck, and try discmakers for production above 1000 cds, they have
especially good deals on digipaks. for inexpensive cdr duplication
that looks nice, try www.diskfaktory.com.

steve