They also serve who are polite. Service with a smile may be staging a comeback

TWO weeks after a woman bought a pair of ivory earrings at a store in suburban Chicago, she received a letter from the salesclerk: ``Dear -----,''

``I hope you are enjoying the beautiful earrings you purchased. They looked stunning.

``If you're ever in the Chicago area again, stop in and see us. It was a pleasure being of service to you.

``Sincerely, -----, Sales Associate, Jewelry.''

A thank-you note from a store? For buying a pair of earrings? The shopper was surprised -- and impressed.

Her letter represents an extreme example of good customer relations, to be sure. But it serves as an indicator, along with the large buttons sported by Marriott hotel employees asking, ``Am I smiling?'' and the rising chorus of ``Have a nice day!'' heard everywhere across the land.

As manners stage a modest revival in the '80s, good service -- the merchandising equivalent of manners -- may be coming back as well.

Corporations dealing directly with the public are sponsoring training seminars for new workers, motivational sales contests, and ``employee of the month'' recognition awards -- all emphasizing that a satisfied customer is a valuable commodity.

No one is suggesting that the life of the average shopper has suddenly taken on a sunburst glow of satisfied requests and promptly handled complaints. But there are rosy signs on the horizon.

Some signs of changing attitudes are largely symbolic and semantic -- euphemistic attempts to upgrade the image and status of those who serve the public. Clerks are now often called sales associates, for example, and bank tellers may sometimes be identified as customer-service representatives.

Other changes are more concrete: better-informed, more solicitous sales and service staffs, store hours adapted to the needs of working women, ``customer friendly'' return policies -- even improved store directories and signs. Comment cards soliciting customers' opinions also appear more frequently in stores, restaurants, and hotel rooms.

As part of a three-year-old Hyatt program called ``Guest Requests,'' employees strive to respond to all requests within 15 minutes.

``Those companies with a handle on service are going to be the winners in the future,'' says Olof Arnheim, general manager of the Marriott Hotel in Newton, Mass. ``Those that do not have a handle on it are going to be the mediocre ones.''

Cynics, blitzed by all this calculated kindness, may wince at the waiter or waitress ordering them to ``Enjoy!'' But are they really that attached to stylish indifference and occasional rudeness? You still don't have to go far to look for examples of such manners.

Recently, as a college-age clerk in a trendy sweater shop rang up my purchase, she continued to carry on a long personal telephone conversation. Details of her day at the beach, arrangements to pick up a friend for a party that evening -- everyone waiting in line heard every last detail of her plans.

Among the people most likely to experience this indifference, teen-agers hold a special place. Teen-agers of my acquaintance complain that clerks often ignore them completely or wait on them only reluctantly.

One girl, blessed with an inventive spirit, now routinely carries a bag from an upscale store -- Saks or Neiman-Marcus -- when she heads for local malls, claiming ``it helps a lot'' in getting clerks to take her seriously.

But considering the buying power teen-agers possess (some $49.8 billion a year at last count), savvy retailers ought to cultivate these youthful consumers. Today's teen-agers, after all, are tomorrow's career men and women, parents, homeowners -- future customers with impressive retail needs.

Nor will true customer care arrive until reconsideration is given to what retailers call ``customer seating.'' Once, chairs were a common fixture in many stores -- in fitting rooms, near cash registers, and in clothing departments. But now that retailing success is calculated in sales per square foot, most of that seating has been replaced by racks -- and more racks! -- of merchandise.

Even in central mall areas where space is more plentiful, weary shoppers must often perch on the edge of cement planters or sit on backless benches. The governing philosophy seems to be: Keep moving, keep shopping.

But the philosophy may be changing.

Sandra Sucher, vice-president of customer service at Filene's department stores in the Boston area, has gone so far as to say that being in a retail business is ``much more like theater than anything else. It's always show time.

``Your job is to treat every customer as if they are the first and only customer you will have all day. The more you can put your heart and soul into it and do it that way, the better it is.''

Earlier this year, a small sign on cash registers at Filene's reminded its clerks to ``Think like a customer.''

Ms. Sucher explains the purpose this way: ``We wanted our staff to keep in mind, `How will this decision affect a customer? If I were a customer and this thing happened to me, how would I feel about it?' ''

The corollary, of course, would be a similar reminder affixed to customers' shopping lists: ``Think like a clerk.''

Think, for example, of being on your feet all day, as clerks often are. Think of the challenge of remaining unfailingly polite while an angry customer complains about a defective or unsatisfactory purchase.

Think of the modest wages.

It's enough to make you say to the next clerk you meet, ``Have a nice day!''