Which of the following is NOT a source of gaming revenue?

Live entertainment is not traditionally considered a direct source of gaming revenue. In the context of a casino or gaming environment, revenue is primarily generated through various forms of gaming activities, which include slot machines, table games, and sports betting. These activities involve gambling and typically have direct financial implications for the casino's income.

Slot machines, for instance, are a major contributor to gaming revenue, with players betting money for a chance to win based on random outcomes. Table games like poker and blackjack also generate significant income through player bets and the house edge. Similarly, sports betting is a growing revenue stream as patrons wager on the outcomes of various athletic events.

Live entertainment, while it may contribute to overall revenue in a casino setting by attracting customers and enhancing their experience, is not a form of gaming. Instead, it falls under a different category, often categorized under attractions or non-gaming entertainment. Therefore, it does not directly generate gaming revenue like the other options do.