they rate an ICO depending on their payment to them?

Yes, I think there is a link or partner. It is in the company's or group's promotion plan. You should not rely entirely on the ico review site. Although it is a popular method for tracking and selecting good ico to invest. However, I do not fully trust them, but I do take other measures such as community exploration, social media, publicity, and, most importantly, practical ideas. team or company focus on building and developing plans and enthusiasm for the project.