I received a textbook this week from Better World Books, a subvendor of Barnes and Noble. It is a heavy  2 inch thick book that came in a poly-envelope that was all sticky on the inside surface.  The inside of the poly is solid black. Has anyone ever heard of a poly-mailer like this?

I got one like that too.  It didn't mess up the book, but it was very strange.  There was also no reusing it once I got it unstuck.  Not that I would have reused it, as I didn't like it to start it with.  I hope it doesn't become a new popular choice.

I agree Darla, it feels like the old "flypaper" Shell strips from the 60's and 70's!  No way I'd ever consider mailing a book in that stuff.  But I wonder--- is it to keep the book from sliding around in the mailer?  The one I received seemed pretty snug to the size of the book so sliding wasn't an issue in the case of the one I got.

I think Better World Books is the only company from which I've ever received a book wrapped in those weird sticky wrappers. It was a large hardback and the postal machines had shredded the wrapper off on several edges, damaging the book. I emailed Better World Books, pointing out that those wrappers just make it easier for the postal machines to abrade the edges and corners of a hardback, and asking whether maybe a box (which they do use sometimes) might protect the book better. They refunded my money for the damaged book and said they were studying the packaging question. I'd guess they have to do a lot of refunding when they use those sticky wrappers, so maybe nobody will be using them much longer. We can only hope...

I've heard of Better World Books, not sure if I've ordered from them...don't recall receiving any mailers that were sticky inside. 

If I received such a mailer, I would probably contact the vender and the seller/site (B&N, Amazon, etc) and let them know that you consider that type of mailer unacceptable and potentially damaging to your merchandise. 

If you don't tell them you're unhappy, the situation is unlikely to change.