Independent book sellers. Sounds weird, why would they give books away for free? I have a friend who sells books online and buys huge lots of books to resell, many of which are not resellable due to condition or oversaturation in the market. I have gotten a truly obscene amount of free books from her because of this. Lots of sellers have books they want to unload and often have to resort to throwing them away.

This is exactly what happens to me when I ask questions in more academic communities. My advice to you is to keep asking anyway. The world has legions of people who need to feel big by making other people feel small. Don’t ever let that get in the way of asking things you want to ask or doing things you want to do.