UPDATE: As of this morning there are now more than 7 million Mastodon users, most from the #TwitterMigration.

In fact, 100,000 new accounts have been created since last night.

Since last night's spike 8,000-12,000 new accounts are being created every hour.

Yesterday, I estimated that Mastodon would have 8 million users by the end of the week. That might happen a lot sooner if this trend continues.
@atomicpoet Great, I think roaming identities could solve the problem of instance isolation. They could fill the role of tinkers and traders with the old feudal towns.