Adsterra is a popular advertising platform that caters to websites which aren't suitable for google ads due to dmca or adult content, if you have a website you can register on adsterra.com and get ad codes for popups, banners, social bar (their exclusive form of ad which you've probably seen here at skidson.online) and much more. Depending on the traffic your website gets you can make a fair bit of money each day as the cpm is quite high.