http://q3o3hdjbia2v4hjag567piljrz6gmfwfmxjzaqq4qstmicnmujxp45id.onion/guides/how-to-detect-scams
No one has 100% good feedback, even Amazon. It's the same here - If they claim to have 100% happy customers then it's a bait. Revolutionary methods to make money like bitcoin generators, monero botnets or gambling games with incredible ROI are scams, again too good to be true Too simplistic websites with just an email address for example, are also likely scams.