very difficult to understand, anyway I understand this:
Let say I'am your top sales referer, I make 10 sales per day, $30 per sales that os $300
Now you have another webmaster sending 1 sale per day, $30
So that second webmaster will get 10% of webmaster 1 (apart from his $30) because he is able to generate 10% of top webmaster
that's why I understood, but still confused
you need to smoke some

first to understand this
