Your Invisible Facebook Friends

By Cameron Scott 

audience size, social media, social network, privacy, reach

KR MEDIA Productions /

Tech insiders frequently reference the fact that most social networks are dominated by a small number of active content creators, while a larger number of users regularly use the platform but rarely or never post content.

Users of social networks, however, have yet to comprehend this dynamic. Facebook users dramatically underestimate how many people see the content that they share, according to a new study published by Facebook data scientists and Stanford University researchers.

Facebook users consistently guessed that the size of their audience was just 27 percent of its actual size, the study found based on the logs of 222,000 users’ posts over the course of a month.

There was no real way for the users to gauge their posts’ reach, since none of the the publicly visible signals of friend count, likes, and comments strongly correlated with the audience size for a single post. Rather than demonstrating a consistent percentage of the number of users who see a post, engagement represents a varying share of the total audience.

“Posting to a social network site is like speaking to an audience from behind a curtain,” the study authors said.

Despite the variation in reach among posts, users generally reached about 6 in 10 of their friends in the one-month period.

The findings suggest that users may be sharing things with people they don’t know are seeing their content. They may forget they’ve accepted certain friend requests, for example, if the other user doesn’t appear to be active on Facebook.

Users also adjust what they say based on whom they believe they are talking to.

“Correct or not, these audience estimates are central to media behavior: perceptions of our audience deeply impact what we say and how we say it,” the study notes.

The mismatch between user perception and reality underscores what many privacy advocates say about social media — essentially that users don’t realize how public much of their content is.

The study’s authors make a similar point, put it another way. While social networking companies often tout the transparent communication their products enable, this study’s findings suggest that social networks are better described as “socially translucent.”