Virality Suffers After Facebook Fix, As Expected

When Facebook announced that they had found a bug that may have underreported Reach for Facebook Page Admins, we immediately assumed that Virality would be experiencing a decrease across the board. We decided to dig deeper after finding that Reach had, in fact, improved for most Pages. Since Reach had increased, it was extremely likely that Facebook’s Virality metric had to decrease.

Virality Drops After Facebook Bug Fix


We measured the past 3 Mondays to see how content has been trending as it relates to Facebook’s Virality metric. Before the fix, Virality was hanging around 2.25%. The past 2 Mondays (post-fix) have remained lower than our original sample.

What is “Virality”?

Facebook defines Virality as: “The percentage of people who have created a story from your Page post out of the total number of unique people who have seen it”. Creating stories can be from Likes, Comments, and Shares of content. Essentially, the more people who engage with your content in relation to how many unique people have seen it, determines a particular post’s Virality.

Why Did Virality Decrease?

Mathematically, Virality had to decrease if Reach increased. Engagement has held relatively steady over the same time periods, and Reach increased. Virality is basically Engagement / Reach, therefore, when the Reach increases and Engagement holds steady the percentage has to decrease. This has less to do with Facebook making any inherent changes to the actual Virality metric, and much more to do with the effects of mathematics.

What We Measured

We analyzed three individual Mondays. One Monday before the fix was implemented, and the two following Mondays. The sample size was roughly 1,000 Pages and all Pages posted on all three days. We are looking at the median of the sample size for each page’s average post Virality.

What Is The New “Average” Virality?


Before the fix, Pages were experiencing around 3% Virality. This number had climbed since we lasted reported on it last March. We suspect the reason the Virality had risen to 3% is due to the steady decrease in Reach over the same time period. The same mechanism that attributed to this steady increase, is now the reason that Virality has significantly decreased.

After the fix, the median is 1.86%. This number has returned to it’s value that we reported in March of 2012 (1.92%). Facebook’s Jason Li recently stated that Facebook suggests to strive for “1-2% Virality” for your content. This lines up with what we’re seeing with the fix being implemented.  


We expected Virality to decrease due to the inverse relationship between Virality and Reach. As Reach goes up, assuming engagement stays steady, Virality goes down. With our report last week that revealed Reach increased it was only a matter of checking the numbers to see how far Virality had dipped. For most Admins this change merely affects your reporting, and we hope this new data gives you a benchmark to better explain to your clients.