Lego store display

[Hippoharbor]

After seeing the really neat Lego Star Wars Darth Vader in my local B&M, I began wondering what happens to all of the displays once they are no longer needed. I would love to get one. Do any of you know how that works? I have looked on Ebay and do see, at times, previous store displays being sold. Do they give them to employees, raffle them off, trash them?

Thanks