Dear Parent:" said the letter from Sesame Street magazine. "The last time I wrote to you, I was concerned. Now, my concern has given way to active worry.

"Because your child's subscription to Sesame Street magazine expires after the next issue. And we still don't have the go-ahead from you to renew it."

Good grief, dear parent. You're falling apart!

"All of which adds up to an imminent subscription crisis. Time is running out. But I will guarantee this: If we get your renewal instructions within the next 14 days, your child's subscription will continue without interruption."

Thank goodness, you might be saying. There's still hope.

"What's at stake is continuity of the opportunity you decided to give your child when you first enrolled him or her as a subscriber."

Continuity of opportunity is the last thing parents would want to deprive their child of, as we all know. The letter continues to explain why. We're not talking about a magazine subscription here, we're talking about a child's future.

"In a sense, you created your own 'operation head start' didn't realize that, did you? by providing the kind of early learning experience experts say can do so much to help a child learn better throughout his or her school and college career. What you're doing, in effect, is to help give your child an edge in the competition he or she must inevitably face.

"Is there any higher priority than this for those of us who have children? Any higher priority than doing everything possible to help your child develop the self-confidence and enthusiasm for reading and learning that are so essential to ultimate self-realization?

"Let me ask you -- are you sure you really want to let this opportunity expire? The opportunity you gave your child when you subscribed to Sesame Street Magazine, one of the most valuable tools ever created for helping children realize their potential?"

"Heavens, no!" dear parents across the country must be saying after reading that letter. What's at stake is not a few dollars for a subscription to a magazine that might or might not ever be read by your child. What's at stake here is your child's competitive edge: the child's self-confidence, love of reading and learning, and ultimate self-realization. Renewal is not a decision to be put off, the letter goes on to say, and if the proper instructions are followed, the magazine will continue to grace your child's existence without interruption and you will "get the satisfaction of knowing an important priority is taken care of."

The mere thought of nonrenewal ought to send chills down the spine of any self-respecting parent. How could you have been so irresponsible as to come this close to a subscription crisis? What kind of parent are you, anyway, going around thinking that just because you are sheltering, feeding, clothing and schooling your child, tending to emotional and physical health needs, that you are doing everything you should be doing? You almost deprived the child of one of the most valuable tools ever created to help realize the child's potential!

This postal-borne guilt trip arrived at the home of a friend shortly after an article appeared in this newspaper that was written by Brad Edmondson and adapted from American Demographics magazine, of which he is associate editor. He makes the point that advertisers are currently having a field day playing on parental guilt -- not only toward their children but also toward elderly dependents.

He cites the example of the Xerox ad that shows a father getting home for his daughter's birthday -- all because of new Xerox equipment in his office -- and the Commodore ad with a kid flunking out of college, "presumably because his parents didn't buy him their 64K home computer in time." Edmondson cites canned good ads that assure busy parents the product is nutritious for our children, nursing home ads that tell us the home is like "grandma's house," airline ads that warn of dire consequences to the marriage of a traveling executive who neglects to bring his spouse along.

The advertisers, writes Edmondson, "are stalking a large and emotionally vulnerable market. The potential targets are those who care for others, and their vulnerability arises from a double bind: a desire to work hard, achieve and make money, and an equally strong desire to be with their families . . . . And the emotional hook is guilt."

Indeed it is, and I, for one, herewith resolve not to buy it. Even without Sesame Street magazine, I got self-realized enough to know that playing on guilt isn't good advertising practice. It's dirty pool.