A narrow notch, groove, or opening, such as a keyway in a piece of machinery or a slit for a coin in a vending machine. Also: a position within a group, series, or sequence: a slot for a new employee at the company; an available time slot for an airplane departure.

With slots accounting for the majority of casino revenue, casinos strive to keep their customers happy by lowering the house edge as much as possible. But some data analysts say that casinos may be chasing the wrong strategy by trying to reduce the house edge too much. Instead, they should increase the frequency of winning symbols and raise the pay outs for those symbols, which would make it more likely that players will stick around and play longer. This is the view of ReelMetrics, a company that works with casino operators and manufacturers to help them solve the problem of player retention. But switching long-standing operating and marketing tactics is a hard sell for many casino managers. They fear losing the all-important slot market to competitors if they reveal that they are increasing the price of their games. And players have a strong tendency to avoid slots that seem too expensive. As a result, casinos often conceal the fact that they are raising their prices by hiding them in the fine print of the game rules. They hope that this will prevent players from leaving and going to the competition.