Casinos make money on poker primarily through the "rake," a small percentage taken from each pot or a fixed fee per hand. This ensures a steady income regardless of the players' outcomes. Additionally, casinos may charge entry fees for tournaments, further boosting their revenue. While players compete against each other, the casino's role as the house allows it to profit from the game without directly betting against the players. This model creates a sustainable business, attracting both casual and serious players to the tables.