On any given Sunday.... the bookies bring in the suckers’ money(is my guess!)
Many people don't understand the way it works. Leaving out the point spread for explanation purposes, let's say you want to win 100 dollars betting on the Steelers and I want to win 100 dollars betting on the Jets. I put up 110 dollars and you put up 110 dollars, with the bookie holding 220 dollars. You win the bet, and the bookie gives you back your 110 dollars and the 100 dollars I lost. But here was a total of 220 dollars put up. You get 210 dollars, and the bookie keeps the "extra" 10 dollars. He doesn't care who wins, but he needs to make sure that by game time, the bets even out so that no matter who wins, he gets paid.