This is done by changing the microprocessor chip in the Player Tracking Device (PTD) in each slot machine, and it's not a simple task. So, their only recourse to maintain profitability is to increase the house advantage (also called 'hold' on slots). Harrah's in New Orleans has always had a problem with patron numbers because most people don't come to New Orleans to gamble. They can increase the number of patrons or they can increase the house advantage. A casino can increase revenue in one of two ways.