I'm going to echo Bitt here. My experience isn't really with old books per say, but still with books that I wasn't sure anyone would want.

Last summer I helped clean out my parents' home and held a garage sale. At the end of it we had about a hundred books, mostly fiction. Most of what was left was of the bestseller variety, mostly thrillers and crime novels (Patterson, Follet, etc.).

Now, I understand that these books do not comprise the greatest nor scarcest literature in the world, but it was shocking how dismissive the people at Goodwill were when we brought them by The guy was almost angry at me.

But the thought of simply throwing these books away just seemed wrong (and they were well-kept hardcovers, too!), so we took them to our local used book store and they took them off our hands in order to hand them off to whichever local library would next have a book sale. We got a pretty significant tax credit for each box of books, too.

I'm sure someone is enjoying a like-new hardcover Robert Ludlum right now that they probably picked up for a buck fifty.