> 100M signups in five days is impressive at first glance. However, if you do some quick math, you will see that 100M signups (defined by install the app + click a button that says signup with your Instagram account) out of 3.8 billion monthly active Meta users is 3% of their users, i.e. 3 out of 100 Meta users did a low effort action (one-click signup) in the midst of a huge product news cycle.

Threads isn't available in Europe (~500M population), Meta MAU != Instagram MAU, and 5 days isn't 30 days.