If you ask me, it's simply a matter of a confused staffer at Wingra Direct or USPC (whichever of the two actually runs Club 808) getting the concept of the size of a brick wrong. The 12-deck brick is an industry standard, it's what wholesalers and retailers use when measuring quantities. Because a complete box of the Club 808 decks is only six, some goofball copy writer mixed up "box" and "brick" when he wrote the copy for the contest.
The only other possibility is that USPC calls a "brick" any box large enough to hold more than a few decks. But that would make ZERO sense, because if I was selling decks by the brick but all the bricks were different sizes, my customers would be scratching their heads and asking if I was stoned or just stupid.
If you look over the decks selling in the Club 808 shop, they still call a "case" 24 decks, just as a case of beers or a case of sodas is 24 cans or bottles.