Well, pretty much every service or knowledge business.  Let’s look at landlording, manufacturing, and small business consulting as three examples.

Landlording is one of those embarrassingly interpersonal businesses:  “Hello? I’m here to unclog your toilet.”  “I’m not dressed!  Just take care of it please!”  Even with toilets that flush buckets of golf balls and other modern housing marvels, you’re trusting a breakable piece of a very expensive asset to a relative stranger.  If they stop paying you or start causing problems, it’s very expensive and time consuming to end the relationship.  After all, their basic home and shelter are at stake, so third party mediation (e.g., the courts) usually comes into play.

Different troubles await manufacturers, especially those offering fixed-price contracts.  If you’re going to accept a job to make 100 of a new kind of widget, you want to feel warm and fuzzy about having the right drawings and knowing that they’re not going to change quantities or specifications once you start the run.  In this case, you have to negotiate for up-charges, or offer concessions, or arrange a (hopefully) peaceful walk-away.

And for small business consulting, where you might feel you want every client you can get, you really want your customers to sing your praises and give you word-of-mouth traffic and their own repeat business.  You definitely don’t want to try to please a habitual grouser, or to keep quoting a lookie-lou, or to otherwise commit to helping someone forever dissatisfied.

So What Can be Done?

Good landlords have a rigorous screening process (never discriminatory, always based on economics!) and so might lots of other businesses, except I very rarely see open communication about customer screening.  As a potential customer for a lot of different services, sometimes I wish I could get feedback:

Dear Prospective Client:

You have had us requote variations of the same thing for the last three months.  We’ll be happy to continue working with you after a one month hiatus, or you can sign and return one of our quotes and we’ll get started right away.

But when does that ever happen?

The best general advice that I can give is that sometimes it’s okay to say no to a prospect.  As soon as you do, you’ll be thinking about the next prospect.  Much better than wishing you weren’t locked into a bad situation.