We do a few things to reduce the risk of abuse from invalid clicks and help improve your ad performance, such as capping the number of times any ad is shown to a person, regardless of whether they click on the ad.

There are two different types of clicks that we consider invalid:

• Clicks from people that don't indicate a genuine interest in the ad or show signs of ad testing. This includes repetitive or accidental clicks and visits from the Facebook corporate network.
• Clicks generated via prohibited means, such as fake accounts, bots, scrapers, browser add-ons or other methods that don't follow Facebook Terms.

If we detect or are alerted to suspicious or potentially invalid click activity, a manual review is performed to determine the nature of the activity. You will not be charged for clicks that are determined to be invalid.

* Nguồn: Facebook