The fastest growing app will have the worst retention rates.

Imagine a world where all users are the same, regardless of social network. Imagine that if 1000 users start using a social app on day 1, that only:
* 900 of them will be using it on day 2
* 800 of them on day 7
* 600 of them on day 30
* 500 of them on day 365

Now imagine if network A hasn't grown in 5 years, but has 100MM users. Network B is doubling every 2 days, and is currently at 100MM users.

Which will have worse retention?

I keep seeing journalists / analysts missing this insight. It's framed as "Everyone is leaving Mastodon!" Or "Threads is already dying!" Neither is necessarily true.

This is a natural phenomena that always happens with rapidly growing apps and networks.

A better way to think of it is "Of every 1000 users who sign up, only 1000/N of them will be here in a year, so discount the growth rate."

It's scary to know what N is. And it changes over time. And it can change rapidly.

@mekkaokereke I would add that after the era of big SM, the public looks for exponential growth without the context that that was part of the problem! As the biggies fall it may take time as we all spread out looking for better.