Interesting,

Everyone's gain is tending toward 0 asymptotically in theory.

You can do some maths :

If you are the first to play : you will win 2 Eth !
 2th : you will eventually regain your 1 Eth
 3th : 0.66 Eth
 4th : 0.5 Eth
 >10th : you will accumulate 0.2 Eth
 >20th : you will accumulate 0.1 Eth
 and so on ...


I don't get why some people invest many times 1 Eth, it won't increase profit at all.