Our leaderboard is there for bragging rights - it shows who's won what over the time they've been with us, and how much people have been paid in our FREE contests (Group and BIG RUSH).
There are no prizes for ranking on the leaderboard, and it's not a representation of money you're going to get paid, but it does reflect the cumulative winnings of the players on the leaderboard.
The leaderboard numbers are representative of cumulative wins - so for Group RUSH and BIG RUSH that's the combined total of all the wins (FREE MONEY) that those customers have received from RUSH simply by playing the contests.
The Weekly and All Time list is also the cumulative wins for those customers. That means if a customer buys a $10 pack and wins $10 in that pack, that's $10 that's going to their winnings. So it's not winnings minus costs, it's just winnings. So it's indicative of either a lot of play, a lot of luck or a combination of both.
Keep watching the leaderboard as it will evolve as RUSH evolves, and perhaps in the future we might even start rewarding people for their standings on the leaderboard....you never know, we certainly like giving away money!