Whales do not really get that much excited on anything other than just competitions that give them a potential to have a positive house edge, aside from that you can't get whales to play. Looking at the competition the rewards are not really that high to justify a whale to gamble anything over 10 bitcoin, sure it is still something that drops the house edge because you get something but compared to other places that gives out tons of money for the competition it is really not that high here at all.

As long as you make a competition for wagering and give people 0.1 bitcoin or more (not the winner but the whole contest) than you may start to see it increase, I am not even sure if anyone gets anything from these leaderboards at all? I didn't see any prizes for being first but it could be something I missed out so I am sorry about that part. There was 28 people when I checked, you just have to do a lot more promotions to increase that, specially for a website this old, you deserve at least 100+