Facebook is by far the world’s largest social network. As of the end of 2015, it had 1.59 billion users, up from 1.39 billion the year before, and it’s adding more, especially in the developing world where inexpensive smartphones are allowing many to go online for the first time.
With such a massive number of accounts, it’s unavoidable that thousands of Facebook users die every day. The exact number is unknown, but if we do some back-of-the-envelope math based on the ratio of the world's population on Facebook (21.5 percent of 7.4 billion people) and how many people are estimated to die daily (151,600 as of 2011), we can estimate that there are probably around 32,600 Facebook users who die each day.
This is a crude ballpark figure, of course. The actual number is likely to be somewhat lower since Facebook users probably skew younger than the general population, but it still offers an idea of the scale of the phenomenon.
You might think that the accounts of the deceased are closed down, but so far Facebook has had the policy of leaving them open in a “memorialized” format unless someone else has access to the account’s password and explicitly deletes it. These accounts add up over time.
Extrapolate on that trend, and eventually you get the unusual scenario of having a social network in which dead users outnumber the living. In fact, all those memorial accounts would form the largest virtual graveyard in the world.
Based on current conditions and if Facebook’s growth starts to slow soon, the "virtual graveyard" effect is on track to happen on Facebook by 2098, according to Hachem Saddiki, a Ph.D. candidate in statistics at the University of Massachusetts. Saddiki's research was backed by Fusion.net, which asked him to tackle the digital tombstone calculations. Of course, that’s a long time in the future, and by then many things could change. Facebook could change its policy on deceased users, or some new social network could emerge, supplanting Facebook.
There’s also a good chance human life expectancy will keep increasing, pushing the balance back in favor of the living. But until then, we can honor the dead by keeping the social conversation going.