The Gary mentioned all over the signage is probably Gary Shapiro, the head of CEA (the trade group behind CES). Do you notice how he is mentioned in larger font than Barnes & Noble? That is probably a sign that this isn't actually B&N's booth; they're simply running it on behalf of the CEA. And that changes everything.
I doubt B&N is actually paying for this booth (or at least they are getting a huge discount), and in retrospect I now doubt that they paid for the booth last year either (kudos to Vonda Z for suggesting that possibility last year). If B&N's only investment is overhead then their costs drop considerably and their presence here is no longer inexplicable. odd, yes, but not inexplicable.