How to migrate from one Mastodon server to another without losing followers:
1. Sign up on new server
2. On NEW server: Go to Account -> Moving FROM another account
3. Enter old account's handle
4. On OLD server: Go to Account -> Moving TO another account
5. Enter new account's handle and submit
@Gargron I actually had to do this when the original instance I signed up on got too slow with all the new members