My first job out of school was for a mom-and-pop manufacturing company. I got an inquiry one day from a very well known company, and mentioned it to the boss. He gave me a long lecture about why we didn't work with that industry. They were notorious for stringing their suppliers along and holding them in a sort of debt bondage. I remember responding with a FAX (yeah, that's how it was done) explaining our terms: Pay in advance. The boss made sure that the business was never beholden to a single large customer.

We also had a draconian, hair-trigger, credit hold process. I remember overhearing the scheduler / receptionist telling a customer: "You are on credit hold right now, we can't schedule your next production run."