Anyone active on Twitter experiences follower churn—the constant arrival of new followers and departure of existing ones. Some arrivals are follow-whores who will leave in short order if you fail to follow them back. Some are fake accounts attempting to build a legit patina. (Fake accounts are easy to spot and I delight in kicking them off my feed.) Then there are real-life porn actors and jihadists seeking to expand their reach. (Blocked and blocked.) Others follow you based on the odd single tweet and depart when they find your regular material is not to their taste. (de gustibus).
In general, one must tweet frequently to gain new followers. If you have a truly loyal set of followers they may stick around even if you tweet rarely.
But what happens at the limit, when an account ceases to tweet at all? In the absence of new material it is unlikely to attract new followers. Existing followers may eventually unfollow, or close their accounts, or be banned by Twitter. Thus we can expect an inactive account to shed followers gradually. But at what rate?
I have harvested data on a weekly basis from several Twitter accounts. One is that of Jonah Lehrer who enjoyed a brief vogue as a literary explainer of neuroscience. (I found him to be a superficial thinker and a lazy scholar; see the Proust chapter in What the Nose Knows.) After it became clear that Lehrer had recycled his own material and plagiarized the work of others he withdrew from the science journo-biz and, among other things, ceased tweeting.
The last regular tweet on @jonahlehrer was dated June 17, 2012. On February 13, 2013 he posted a link to the text of a speech he gave to the Knight Foundation in which he apologized for his behavior (and for which he was paid $20,000). After that, nada.
So how did Lehrer’s Twitter followers react after he went silent? Well, here’s the answer, based on weekly tallies from October 14, 2012 through December 31, 2016.
Over that period Lehrer lost 6,258 followers. Their number declined to 40,620 from 46,878. The steady decline was interrupted by three increases: a spike of 2,005 followers the week of October 28, 2012; a blip of 369 followers around May 2013, and another spike of 1,998 in the week of August 24, 2013. (Cynical readers might note that Twitter followers can be bought by the thousand online. Whether something like that happened here, I cannot say. The spikes remain a mystery.)
Aside from the anomalous spikes, the decline in followers shows a remarkably steady linear trend. I analyzed the 173 weeks following the second spike, during which the follower count dropped to 40,620 from 47,800 for a loss of 7,180. Over that interval, Lehrer lost on average -0.0935% of his followers each week. Based on this rate of decay, the half-life of his following is 741 weeks or about 14 years. In other words, he should be down to 20,000 followers in 2031. We can expect him to dip under 100 followers in the year 2140.
That’s one long, shallow glide path.
Is Lehrer’s case typical? Who knows. Maybe his followers are fanatically devoted and waiting, year after year, for him to return to Twitter. Or maybe they never noticed that he left in the first place. Having once clicked “follow” they remain fixed to his account like so many barnacles on the bottom of a boat.