This document discusses why achieving true viral growth is difficult for SaaS products. It provides examples showing that even with high user engagement rates, the viral factor (new users signed up per existing user) is typically around 0.01 or less, far below the levels needed for exponential growth. It emphasizes that going viral requires a product that people use frequently in a way that naturally encourages sharing, not just one-time actions like invites or tweets. Product-market fit, daily usage, and high retention are more important factors for growth.

1. SaaS products
aren’t viral*
*usually

3. “How do I go viral?”
Going viral = Sustained exponential growth curve with
zero cost of acquisition, not just a marketing stunt

4. You can’t.

5. (usually)

6. “Why not?”

7. Viral growth, the
analytical way.

8. 1000 new users
20% send out invites
10 invites sent per user
50% of emails are opened
5% click through
20% sign up
= 10 new users sign up
Viral factor = 10/1000 = 0.01

9. 1000 new users
30% connect to Twitter
20% tweet your link
100 average followers per user
1% tweet CTR
20% sign up
= 12 new users sign up
Viral factor = 12/1000 = ~0.01

10. 0.01 is a waste of time.
3000
2250
1500
750
0
1 2 3 4 5 6 7 8 9 10
Viral factor 0 Viral factor 0.01

11. “How do I go viral?”

12. 100X

13. 100X*
*you’ll never get there

14. 1000 new users
20% send out invites
10 invites sent
50% of emails are opened
5% click through
20% sign up
= 10 new users sign up
Viral factor = 10/1000 = 0.01

15. Not a feature.
Not an incentive.
Not after purchase.
Not just once.
Something everybody does, every day, that makes a
high-frequency, high-retention product even better.

17. 1000 new users
20% send out invites
10 invites sent
50% of emails are opened
5% click through
20% sign up
= 10 new users sign up
Viral factor = 10/1000 = 0.01

18. Targets extroverts.
Anyone can use it.
The more the merrier.
Sharing/communication.
Utility + One job title = Fail.

19. 1000 new users
20% send out invites
10 invites sent
50% of emails are opened
5% click through
20% sign up
= 10 new users sign up
Viral factor = 10/1000 = 0.01

20. “Law of shitty CTRs"
Year CTR
1994 78%
Hotwired.com
2011 0.05%
Facebook

21. New channel.
Compelling pitch.
Low competition.
Highly optimized.

24. Product/market fit.
Daily usage.
High retention.
Share files.
Already growing fast.
<1 viral factor.

25. ...

26. “What about me?”

27. You’ve already chosen.

28. Based on your product:
1. Don’t bother
2. Or, drive down CAC
3. Or, go for it*
*probably not

29. Andrew Chen
voodoo@gmail.com
@andrewchen
http://andrewchen.co