Cool downs are one anti-gaming mechanism you can use to prevent users from gaming your gamification system — that is, attempt to cheat or to earn points by exploiting loopholes.
If you follow IndyCar racing, you may be familiar with the push to pass feature. When a driver presses the push-to-pass button on his steering wheel, the car receives extra horsepower for a few seconds, enabling the driver to pass the car ahead (or defend against one creeping up from behind).
So, what’s stopping the driver from pressing that button all the time? Simple. IndyCar officials implemented a cool-down mechanism. After the button has been pressed, drivers must wait a certain period of time before pressing it again.
A similar approach is used as an anti-gaming measure. With cool downs, you wait a certain period of time before rewarding a gameplay behavior. For example, if you reward users for visiting a page, you might require a 30-second gap between each page view. This increases the likelihood that users are actually doing what you want them to do — in this case, reading the content on the page.