This action gives you another +10% bonus and a -13.5% break even time!
This is wrong!
Look at this message:
https://bitcointalk.org/index.php?topic=80845.msg3227985#msg3227985First level sponsor gets +10% bonus and +10.5% revenue (not +15%) so reduction of break even time is about 5%.
I'm afraid all the math on your site is wrong... sorry.