Good type of game and very transparent as you results are coming from the blockchain.
Non of this type are popular now but if you could improve this, then maybe in the future you'll get more gamblers to play.
I check the smart contract but all transactions are going in and no out going transactions and I think this means that it's hard to win for a 50/50 chance.
If it's fair then I guess there are people who can win, maybe because it's quite new thus you don't see some winners yet.