It would be profitable to know in advance who is going to be a “good” and “loyal” customer — one who patronizes your services frequently, spends money on your products or services, and is always pleasant and courteous to deal with.

You could provide that customer extra services, knowing that your investment would reap benefits in ensuring his even longer-term patronage.

If you knew in advance that a particular customer was going to be a consistent problem — always complaining, always returning merchandise, soliciting your employees’ advice before they buy from a competitor, always berating your employees — then you could change your behavior to discretely encourage this problem customer to “shop” elsewhere.

How could you accurately pre-identify which type of customer this person is so you can know how to proceed appropriately? Do you bend the procedure on returning used merchandise, based on your assumption that this could be a valuable customer who would seldom do such a thing?

Do you strictly adhere to the policy on used merchandise because you suspect this person standing in front of you is going to be a problem, and who cares if they never shop with you again?

One store owner told me that one lady appeared to be a “regular”customer. She was in the store several days per week and always bought something.

However, her history was that she usually returned the items she bought and made a scene if she encountered resistance in returning her items. So, sure she was a regular. But was she a “customer”?

How do you assess this in advance? By the clothes the person is wearing? I’ve met many a scam artist dressed impeccably while a really nice fellow is dressed in scrubby jeans and dirty T-shirt (his work clothes).

Do you give preference to someone who speaks in cultivated words and dismiss the guy with poor grammar? Is the fellow who purchases a big-ticket item once in 10 years a better customer than one who patronizes your store every day for 10 years, buying little stuff for around the house?

Oh, to know in advance. But here’s the problem in prejudging the long-term value of a customer: you could be dead wrong in your assumptions.

You’ve never seen this shopper before. You don’t know who they are or who they know.

If you assume you’ll never see them again, that there is no long-term value in their patronage, you could be alienating their relatives who, unbeknownst to you, are your best customers. You could be alienating a newcomer to your town who was exploring different local stores to be his “go-to” store for when he needed something.

I recently moved to a small village and while waiting for my new abode to be readied, I patronized pretty much every restaurant in town. One restaurant in particular assumed that since I was a stranger and would probably never be seen again, serviced every other diner in the restaurant — even the ones who walked in a half hour after me — figuring that they would take care of their friends and neighbors before servicing a stranger.

Wrong assumption. And no, I have not returned, in essence fulfilling their assumptions that I would not be seen again in their restaurant!

You also can’t predict how often a new customer will shop at your store or use your services in the future without a crystal ball.

The solution is to give every customer your best until you have a solid history of that person’s behavior and interactions with your store. You will know a customer’s long-term value when the long term has passed. The past really does predict the future.