Nothing at all stopping new sites from coming up. And indeed that's what is happening. Yahoo!, Draft, and a dozen other sites offer almost the same product. The plan to go with the massive overhead of non stop ads to get the big market share isn't working out so well.

But yeah the 150 entries into big tourneys isn't helping either. The players at the top all know the guys taking down the big tournaments, for the most part. However, a much bigger deal was the fanduel employee winning 6 figures on draft kings using info that other players didn't have access to. That incident damn near killed the industry by itself. If it's all insider trading there's no point for the average "investor" to surrender their money.