When you invest you are helping fulfill the bankroll of the site.
Based on the % of bankroll that you fulfill you will be paid on all site earnings.
Your cut of the site earning is 90%.
Which means you will split 90% of all earnings between all the investors and yourself.
The amount you receive out of that 90% is based on the % of bankroll that you are fulfilling.
The more you invest the higher your % of the bankroll that you fill.

You can see what % of the bankroll you are fulfilling on the 'Invest' tab.
It is displayed as 'You are supplying 20%' or whatever % you are supplying.

If you have nothing invested it will display as you are supplying 0%.

Although we have a 2% house edge, and in the long run will earn a profit of 2% of the wagered amount, in the short to medium term we can still lose money. In times when we are lucky, we win many bets and earn a larger-than-expected profit, and in unlucky times we earn less than expected, and can even lose out. This is especially so if someone comes in and makes a large number of massive bets; we can either gain a lot or lose a lot. If you believe that the potential gains do not outweigh the potential losses, please do not invest.