I've been sending paperback books in boxes but I want to make the switch to padded mailers. Amazon seems to be full of mixed reviews regarding these things. I'm open to buying them elsewhere if needed.
I find padded mailers to be more protective than boxes. The Amazon-style boxes that their books arrive in often come damaged at the corners, thus folding the edges of the books somewhat. This has happened quite a few times with me. However, with padded envelops, the chances of damage to the book is considerably less, I have seen. Also, postage-wise, I believe mailers will be cheaper than boxes.
I use padded mailers to post mail games and I have not had any problems. Not sure about books though. If you do decide to go with padded mailers look for the jiffylite ones, the quality is good. It makes sense what Gina posted about boxes though, being cheaper and having less chance of getting damaged.
Yeah, I've been loading the boxes with bubble wrap to mitigate the effects of damage as much as possible. I'll check out the jiffylite mailers, Spykz. Thanks.