Try The Granza "GO VIRAL" Calculator:

How much time, effort and money would it normally take you to get these results?
Fill out both steps below. Step 1 is your only job, so the more the better. We have used reasonably conservative assumptions.*

(These new Granza users become your Level 1 downline users.
These new Granza users will do the same thing as you-invite their OWN Level 1 users, and so on with each new user in the chain.)
Downline
Level
GRANZA users that will see your ad Your new email contacts
Level 1 0 0
Level 2 0 0
Level 3 0 0
Level 4 0 0
Grand Total 0 0

*The calculator results are based on a 2% average email subscriber rate, an average initial Granza user email contact list size of 300, and a 0.5% average that will
join Granza as new users via that list. Includes 100% ad visibility on Levels 1 and 2, 80% on Level 3 and 70% on Level 4.
Your ad on Levels 3 and 4 are randomly swapped out with non-competing premium ads.