K-factor

What is K-factor?

Mobile advertisers refer to K-factor as a metric that shows an app’s virality by taking into account the number of new users that are generated by each existing user.

Don’t confuse K-factor with Organic Uplift or organic multiplied, however. Even though they are in the same category of organic-focused metrics, organic uplift shows the correlation between organic and paid installs.

Some say that the K-factor is one of the most important metrics for app developers. Apps with a high K-factor don’t need to spend that much money on user acquisition campaigns. They can rely on the organic virality of an app. However, creating a viral app is not easy. There is no formula for a viral app that users can recommend and send to each other.

However, there is a formula to calculate the K-factor.

What is the formula for K-factor?

K = i * c

i - stands for the number of shares per user.

Example: Jack really likes his new podcast app. He shared the link to the app with 5 of his friends. For the sake of this example, let’s imagine that all other podcast users are doing the same thing.

In this case, i = 5.

c - stands for the conversion rate for each share.

Example: Susie and two of her sisters have received an invite to download the podcast app from Jack, but they already have their own podcast app where they are currently listening to a hiking podcast. Therefore, they decide to ignore the invite from Jack. It turns out that only ⅖ users accepted Jack’s invite. Again, for the sake of this example, let’s assume that this holds true for all the recipients. Then:

c = ⅖ or 0.4

K = 5 * 0.4 = 2

K=2 * 100 = 200%

A K-factor of 200% is great. However, it’s not very realistic. If this were the case, Jack’s new podcast app would be a viral sensation. Keeping in mind this K-factor, we can say that your initial 100 users will turn into 300. In reality, however, it’s not that simple because you will always have to account for your churn rate, and newly acquired users through user-acquisition.

What is a good K-factor?

As a rule of thumb, it is important to note that the K-factor should not be higher than the churn rate. If that were the case, it would imply that the K-factor is good enough.

Interesting Fact: K-Factor was initially a medical metric. It indicated how quickly a disease spreads.
How can I increase the K-factor?
We’ve summarized some of the things you can do to increase the K-factor for your app below. However, we believe it’s a best practice to use these points in synergy.

The most obvious way to increase the K-factor for your app is to develop an app that everyone would want to share. At least a good enough app with a cool concept. What would make you share an app with a friend?

Start measuring the K-factor early on, and iterate on things that might boost the K-factor

Incentivize users to share your app through rewards i.e. prompt them to invite a friend and get a $5 voucher

Incentivize uses to share through in-app mechanisms i.e. prompt them to invite a friend to battle against them in a gaming app

Find your audience. Try to find ‘Jack’s’ from the example above. You can segment this audience by country, interest groups, and source