We did a Google search online and found that many other small websites had encountered the same situation as us. Everyone was full of complaints. How could Google not know about it? Of course, Google knew. However, the more we complained, the more we were actually helping Google enhance its reputation.
The webmasters of these small sites would never make a fuss over a few advertising fees. Even if they did, they couldn't compete with Google. By sacrificing the interests of these small websites, first of all, it served as a warning - don't think you can cheat the system. If you do, we will cancel your ads and won't pay you for the previous ones. Secondly, it enhanced Google's reputation - go ahead and complain, this way advertisers will know that we are always protecting their interests. It's like getting you to advertise for us for free.
The more the small webmasters complain, the more at ease the advertisers become - look at Google, they really take our interests seriously.