1% seens a bit high for the house edge.
Even at a casino with unfavorable rules (3x odds) the house edge is like .3 to .5 percent.
Which also, why not make it craps vice just high low.. i realize the programming might be a little more difficult , but for a social network, Craps is like the perfect game... its the most social gambling game out there. (and im sure there are already existant libraries to control a craps game)