Suggestion, allow players to reset their profit/loss counter. A psychological placebo of sorts. I never gambled in my life but thought to try it since I'm an investor. I lost 0.5btc in about an hour. Now every time i come to the website i get this glaring -0.5 in the profit column that just screams "you are a looooooser". this is probably a healthy deterrent but allowing a user to refresh to 0, at their own choosing, would help them keep the thrill.
Yeah this is a good point, when someone walks into a casino if they were reminded how much they have lost over their lives playing it might ruin the fun for that evening. Allowing for counter reset would be a wise move.