“Companies will fire employees who end up not being a good fit, but let customers that aren’t a good fit wreak havoc.”

“We therefore created a series of trigger phrases that, when they showed up in support tickets, emails, or via our onboarding form, flagged a company as a bad fit. If they’re a customer, we then automatically refund and lock their accounts. If they’re not a customer, we simply block their domain from ever signing up.” “To get off our block list, companies have to...”

And using the above as their not-so-secret sauce for developing a great product, for reasons given in the article.