I assume you're talking about the general case rather than AirBnB specifically? Tell people why they're being banned. There is no excuse not to. I can imagin

I assume you're talking about the general case rather than AirBnB specifically? Tell people why they're being banned. There is no excuse not to. I can imagine a B2C freemium product with a high rate of abuse where the non-paying users aren't given the appeal option. But if somebody is paying you, you should have a human driven appeals process. There are certainly cases where customers aren't worth the support cost. Many years ago a SaaS I worked for cut out its entry level subscription because those customers represented most of the support load while also being a minority of the revenue. If you are a monopoly or oligopoly... it might be worth considering what happened to the taxi industry when Uber came to the scene (even before UberX). Years of underwhelming service and zero product development translates to zero customer loyalty. Choice will arrive sooner or later.