I don't know what other site owners say because I don't belong to any other sites. And we're not a GPT, we're a rewards site. So our advertisers tend to treat us pretty well because we are known for having high quality. I've never heard anything about gmail addresses or any other host. All I know is what we have in our rules. Only sign up for things that you are genuinely intersted in. Don't use any fake information when you sign up. If I hear anything otherwise, I will definitely let everyone know.