Here on Vegascasinotalk (VCT), AP stands for "Advantage Player" (a player who only makes a bet at the casino when they have the edge or to gain an edge in the long run) Hawkesite.
How does one get an advantage, card counting??
Sometimes casinos will run promos. Like earn 500 points and get a new mid-range blender which you can then flip on E-Bay for $30. If you play the right machines you can theoretically lose about $10 which means you net +$20 profit. Easy Peasy.
After Ebay's ridiculous fees, you'll still end up losing money on that deal.