I could be 100% wrong but I don't trust primedice from my experiences and what I've seen with others, that's just my honest opinion. Call it bad luck or whatever but I see alot of really strange behaviour, uncanny bad luck for alot of people, not just losing the bets but the timing of losing the bets and the crazy losing streaks just at the right time. The provably fair thing is so complicated to most users that they could be screwed over but just can't understand it so accept that it's fair. All I hear is 'ask dooglas' he'll say its fair, you mean that other guy who also runs a dice game site? And how do we know the primedice verification websites aren't run by affiliates? Again I could be 100% wrong but this is just my honest opinion how I feel.
What I see is a lit of users complaining when they just loose a little. If you see how much High Rollers win last weeks then it looks like its all fair to me. If they would cheat they definitely do it at the high rollers and don't let them win 50 BTC in a few hours.
But if you believe they get rich by screwing low rollers, you need a doctor.