How do you guys spot scam betting sites ? Which are the red flags with those kind of sites and do you believe the rating/review sites or they are mainly paid like the ICO review sites ?
A little google search can save you from scam betting sites. If you come across a cryptocurrency betting website and you want to know about the reputation of that website, try finding its thread in bitcointalk forum. See if the thread is active and if the old members are rating it well. That is when you know the difference.
But you must be careful, because many people who provide false information, because it could be the owner of the website scam (fraud) or cooperate with the website of the fraudsters.