Another thought is simply to give away the Demo CD as added value at retail with the purchase of any BONE comic. Doesn't even have to be inserted into the book - maybe a removable sticker on the cover that says "Get your FREE BONE PC Game demo CD when you buy this comic. Ask at the counter" - then the store attendants just hand out the demo CD with any Bone comic purchase.
Make a few posters to be displayed in-store too to catch the attention of those not specifically looking in the BONE section.
This is the way music stores give away t-shirts, posters, promo CDs etc.
Oh, and would some kind mod please move this thread over to the new BONE forum? Thankee!