Ha, I guess one of us misinterpreted the statement:

"approximately 20% of active users (7.5% of total users) are paying users by month 29"

Is it "20% of active = 7.5% of total", or is it "active = 7.5% of total" ?

It seems a little ambiguous. But to be honest, I think a more reasonable number is 7.5% indeed!!