people wil want killer functionality to switch
All I can offer is my game. If people want to play, they'll play.
The game is this: A number is drawn and the highest bet (in satoshis) that is strictly less than the draw wins.
The draw is taken from the least significant bits of the hash of a block in the blockchain, so it is fair if you assume no miner collaboration.
In order to incentivise play, every pot will pay out at least 1 mBTC (I'll raise this minimum payout as interest increases)
There will be a draw every 48 blocks, or about once every 8 hours. There will be 4 games: the 24 bit draw, the 32 bit draw, the 40 bit draw, and the 48 bit draw. These will have "bet cutoffs" of up to 0.16777216, 42.94967296, 10995.11627776, and 2814749.76710656 BTC respectively.
Example: If the bets are 0.01, 0.02, 0.02, 0.05, 0.08, and the draw corresponds to 0.05 BTC, then the pot of 0.18 is divided equally to the two 0.02 bets.
I'll be launching the site in about 18 hours; the first pot will be sometime after that.
"Premium" accounts for life (lower house edge) for anyone who helps me test my game in these early days.