The daily profit  from a casino’s point of view. Usually the win amount is calculated per day, and refers to the [amount played on the game] – [amount paid back to the player]. This value is often used to gauge how well a gaming machine or a table is performing in a casino.

If a slot machine does a Win per Day of $100, that means that the casino made a $100 profit from this machine that day.

(Win per Day does not clarify how much turnover the machine had, so it could be someone played $100 and lost it all, or many people played and turnover was $10,000 and $9,900 was paid back to the player)