This is how it works

Business 1 pays for business 2 @ level 3

And business 2 pays for business 3 @ level 4

And every one is to upgrade 4 times in the stage 1 business

First upgrade is 1k

Second is 3k

Third is 8.9k

Fourth is 26.7k

People from level 1 pay you 1k each, you'll be making 3k

From level 2 pay you 3k each, you'll be making 27k

From level 3 pay you 8.7k each, you'll be making 240k+

From level 4 pat you 26.7k each, you'll be making 2.1million+