My wife always has the most interesting “customer service” experiences.

This weekend, she visited the local farmers’ market. Now, in this part of the country, farmers’ markets are an emerging feature of a minor economic and marketing revolution: perceived superiority in quality, convenience, flexibility and intimacy between merchant and customer. In other words, an alternative to mass-market, one-size-fits-all industrialized economics. Sounds reasonable, right?

Unfortunately, since marketing and economics are social sciences, they are subject on whatever scale — small, or large — to the quirks of human behavior. As a result, the things we dislike about impersonal, mass-market economics easily and often show up when dealing with the “little guy” as well.

So:

A little old lady who makes homemade dog biscuits has a booth at the local farmer’s market. She sells her biscuits six for one dollar. So far, so good.

My wife, who on occasion can be reasonably frugal, wants to buy some biscuits but doesn’t want to be stuck with them if our notoriously fussy beagle doesn’t like them. She offers the little old lady a deal: will she sell her three biscuits for fifty cents?

Absolutely not, says the old lady. The biscuits are sold six for a dollar.

After some discussion, she remains intractable on this point — she has to have a dollar for six biscuits. She loses the sale.

Our little old lady could have sold my wife three biscuits for seventy cents, earning (1) a per-biscuit profit margin forty percent higher than usual; and (2) an enthusiastic, satisfied customer who would, in all likelihood, return next week.

So what’s the lesson for marketers and congregants of the church of the customer? In today’s marketplace, where a customer can get virtually anything in any configuration for any taste, preference, fashion or budget, scarcity is king.

Smart marketers realize they’re not really in the business of selling dog biscuits (which are only a commodity, easily and cheaply duplicated); they’re in the business of selling scarcity — in this case and others, it’s flexibility or a custom solution or personalized value.

An unwillingness or inability to offer flexibility is a huge liability. “One size fits all” is a commodity and companies who sell only commodities are increasingly becoming roadkill.

Sell us something scarce with that commodity — personal attention, creativity, flexibility, a solution that meets our needs (not your production/volume/sales imperatives) — and you’ll acquire a loyal, high-volume customer.