Ghost ads are a method for measuring the true impact of digital advertising by comparing user behavior between people who saw an ad and those who didn’t—without removing anyone from the campaign. Instead of withholding ads entirely, advertisers intentionally lose the bid to show an ad to a control group. The system still logs when an impression would have been served, allowing for clean, in-target comparisons without disrupting campaign reach.

How Are Ghost Ads Used in Digital Marketing?

Marketers use ghost ads to measure incrementality—the difference between users who were exposed to an ad and those who were not. This helps determine whether a campaign truly influenced behavior like clicks, conversions, or purchases. Ghost ads offer a more scalable and cost-effective alternative to traditional holdout tests or PSA controls, and they’re supported by major platforms like Google and Facebook as well as programmatic DSPs.