Re: What percentage of betting players are long-term winners?
I have repeatedly come across the fact that the number and popularity of casinos and bookmakers is growing in the world. But what are the reasons for this?
Online casinos have become so popular recently and that is the main reason for the popularity that casinos and betting platforms are receiving these days.Quote
1. What percentage of betting players are long-term winners?
Quick search and this is what I found first: 
There probably are researches from reputable universities out there but this is the one that came up front from a search. I am sure that if someone decides to make a deep dive they can find similar researches.