Measuring “viralness”

Just read a post by Josh Kopelman. He talked about what is viral marketing and what isn’t. Great read. Specificially, he believes that a viral product is “one where a consumer’s basic usage of a site/product brings new users (and therefore additional utility) to the site/product.” Josh referred to the term viral coefficient, which is loosely defined as the number of times the user base of a product/service increases in a week. For example, a viral coefficient of 2.0 means the user base doubles every week.

I’ve been wondering about something similar lately. I’ve heard from other Facebook apps developers that any lousy FB app will get you 500 “adds” when you hit “Newest” in the Facebook application directory. Then you run into the repeat user “half-life” (opposite of viral coefficient), i.e. how long does it take to lose half your active users. A half-life of 1 week means you’ll lose half the users in a week. Then another half in another week. (The mathematician in me says that you’ll never get to zero user.) The active users decline rate (i.e. half-life) reflects how good the app is.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: