Thanks for this writeup. Whenever people complain about some service removing or making it harder to try out a free tier, I think they don't realize the amount of abuse that needs to be managed by the service providers.

"Why do things suck?" Because parasites ruined it for the rest of us.

> We have to accept a certain amount of abuse. It is a far better use of our time to use it improving Geocodio for legitimate users rather than trying to squash everyone who might create a handful of accounts

Reminds me of Patrick McKenzie's "The optimal amount of fraud is non-zero" [1] (wrt banking systems)

Also, your abuse-scoring system sounds a bit like Bayesian spam filtering, where you have a bunch of signals (Disposable Email, IP from Risky Source, Rate of signup...) that you correlate, no?

[1] https://www.bitsaboutmoney.com/archive/optimal-amount-of-fra...