The engine part is looking for users that are somewhat, but not totally satisfied and building for them.
That is - you don’t want to build for people that already love your product (it’s already great for them!) and you don’t want to build for people that absolutely don’t like your product (would need a very different product), but instead build for people that you can convert from “somewhat like” to “love”.
> TFA says finding product market fit is when 40%+ of users would be “very disappointed” if your product disappeared.
> Wait! That means, if the only person using your product is your mom, you have PMF.
This just seems straightforwardly correct. If you want to find the size of your total addressable market, use a different tool; this one is for product market fit.
Wait! That means, if the only person using your product is your mom, you have PMF.
Based on what you said and the TFA, this is Superhuman’s PMF approach (i.e., perversely satisfy this metric by filtering users).
I don’t understand where this “engine” is, but perhaps that’s it.