Frequency capping is an important concept in digital advertising in which you limit the number of times that any one person sees your ads (frequency itself refers to the number of times that the same people see your ad repeatedly). Sometimes you can do this automatically, as in the case of Google remarketing, and other times you need to do this manually, as in the case of Facebook advertising. With Facebook advertising, typically you’ll see your ads lose their effectiveness as the frequency rises, and your audience gets too used to seeing the same ad. With Google remarketing, you want to limit your ad frequency to avoid making your audience feel too surrounded by your ads, because remarketing shows your ad in such a wide variety of context that it can make people feel uncomfortable if the frequency isn’t closely monitored.