Just around 24 hours after Musk made his comments, more than 42,000 new users joined Bluesky, making it the biggest signup day yet for the currently invite-only platform that launched earlier this year.

Bluesky saw a total of 53,585 new signups by the end of Tuesday, September 19. The new users gained in that single day make up 5 percent of the platform's entire user base of 1,125,499 total accounts.

The new user signups are tracked via the third-party website "Bluesky Stats." Looking over Bluesky signup numbers on the tracker for the past month, it appears that the platform usually sees from 10,000 to 20,000 new signups per day. Bluesky has doubled its usual daily new user numbers already, with many more hours left in the day still to go.

It's impossible to know whether Musk's comments about charging users to post on X really played a role in this, but it almost certainly had some effect.