Facebook Cookbook

Measuring Your Success

—Jeffrey Tseng (see his bio in Contributors)

Problem

Which metrics are important to measure in order to ensure a successful application?

Solution

The two key metrics that need to be closely monitored to ensure a successful application are:

• The viral factor, sometimes known as the “k-factor,” an indication of viral growth

• An engagement metric, oftentimes application-specific, as an indication of how much the user interacts with your application

Discussion

Metrics are one of the keys to developing a Facebook application. Similar to any consumer web application, it is almost impossible to predict user behavior. As such, the most successful application developers tune their apps extensively through the process of trial and error. To accomplish this, developers must use metrics to measure the effectiveness of the changes they have made to their applications so that they can quickly iterate to achieve their goal of creating a successful application.

Virality

K-factor = [(total number of users converted through installs) + (total number of users converted through Notifications) + (total number of users converted through emails) + (total number of users converted through Feeds) + (total number of users converted through Profiles)] / total number of installs.

The k-factor indicates how viral, or how rapid and self-sustaining, the growth is. This number represents the number of new users that an existing user gets to install your application. If the k-factor is less than 1, the ...