simple maths will tell you what to do 
The numbers of makeBTC
level number of people who made a depossit
1 19
2 34
3 45
4 56
5 61
6 67
7 74
8 77
9 84
10 92
11 103
12 108
13 131
14 144
15 180
16 ??
So you can see there are still people in world population to make it easely to level 200.
Still will get uncontrollable
If you are talking long term yes it is uncontrollable, except if you change the rules along the way to keep it going
And you have to admit it could still go for a while before it stops or slow down a lot. A lot of new money was deposited and a lot of old players sold their level so we are looking at new players that will keep their income invested for a few levels
I won't advise anyone to play though because it would be like advising someone to play dice or roulette but it is definitely fun while it lasts and I except to get my money back within a few banks; play responsibly and have fun!