Between accounts of users who have never really used Twitter, and those behind which bots or spammers hid, this involved a substantial number of accounts.
So much so that Jack Dorsey, the CEO of Twitter, said he lost no less than 200 000 subscribers. Apparently the man counted a large number of "ghost" followers, much more than normal in any case, since the Twitter estimates indicated that most users would not see a drop of only 3 or 4 subscribers.
As the CEO explained earlier this year in an interview with Harrison Barnes, the main change he would make if he launched Twitter today would be to give much less importance to the number of subscribers.
Twitter also reassures that the purge will not affect the statistics it publishes to investors, in this case the number of active monthly or daily users. "Deleting these accounts has no impact on these statistics," says Twitter on his blog.