What are Ghost Sites?
In terms of ad fraud, websites that have been set up with the sole intention of fraudulently generating revenue by serving ads to bot traffic. Publishers of these sites often design them to look like real websites and then monetize them through the programmatic RTB system. Very few, if any, humans visit them and almost all the traffic to them is fraudulent. Bots are often programmed to visit numerous ghost sites to click and interact with the advertisements.