Vouchers.

[ldawg-dvd]

 I have received items with vouchers or gift certificates in the package sent by the seller not by eBay. (Just in the box with the items) 

 Where do you get those or how does that work because I was wondering how or where to get those to send with my items. 

 I'm guessing it's some kinda affiliate program and maybe just a way the show customers appreciation. 

[12345jamesstamps]

I would assume the seller gives you a discount on shipping or something. It comes from the seller and you might want to ask the seller what it means.