Move over, Heather Locklear. In Madison Avenue’s endless quest to break through the advertising clutter, marketers are filling the airwaves with serials of their own. Lately they’ve been hawking everything from phone service to low-fat cookies. Not all their attempts have been memorable. But some marketers are cashing in with advertisements-cum-soap-operas that attract viewers more effectively than a talking head ever could. Let’s face it, says Advertising Age columnist Bob Garfield: “People like these stupid little melodramas, meager as the stories may be.”

The genre made its debut in the late 1980s. Miller Brewing Co. launched a six-part serial called “The Case of the Missing Case,” the story of a tough guy searching for a case of Miller Lite. Two years later Nissan told viewers the story of a couple’s 6,500-mile trek from Chicago to Rio de Janeiro in their Pathfinder. Perhaps the most poignant of the episodic ads was Nynex’s “Jill and Dad” campaign. The series told the fictitious story of an estranged father and daughter who had not spoken with each other in two years. Before the pair was telephonically reunited courtesy of the New England Telephone division, viewers became so involved with the dysfunctional duo that highway billboards and local talk-show listeners urged Dad to “call Jill.”

“Jill and Dad” helped pave the wave for possibly the most celebrated commercial duo in recent memory: those lusty Taster’s Choice lovebirds. For the past four years the lovers have built a passionate relationship around jars of instant coffee, while spouting such gripping, innuendo-filled dialogue as: He: I got your telegram. She: I just had to come to Paris. He: This is wonderful . . . the view, the Taster’s Choice . . . She: Is that all? He (drawing her into an embrace as tender as it is passionate): No.

The latest wave of ads has soared to still greater heights. Kraft General Foods recently introduced a Mickey Spillane-type detective and his voluptuous neighbor Annie, who appear destined to solve life’s mysteries over an economy-size jar of Miracle Whip. New versions of the commercial will air late this year.

Nabisco, meanwhile, has used the sitcom formula to turn around a production shortfall. The company is airing the mythical adventures of Cookie Man, a hapless baker who is tailed by three suburban housewives who can’t get enough of his low-fat confections. The plot is only partly fictional. Because demand exceeded supply for Nabisco’s SnackWell’s cookies, consumers have had problems finding them. One of those customers: the copywriter’s own mother, who engineered an intelligence operation to find out when a truckload of SnackWell’s Devil’s Food Cookie Cake would arrive at her local market. “People related to the problem of not finding them,” says Jean Thomas, business director of Nabisco Biscuit Co. “They liked the characters and thought they were funny and real.”

Why are advertisers putting their faith in serial spots? Studies of soap operas show that fans identify personally with the characters they watch and may even imitate them. In the case of the commercial soaps, says Carol Moog, a marketing consultant and psychologist, viewers go one step further and identify with the product being featured. “Taster’s Choice becomes the catalyst, the intermediary, the friend that brings the other friend over.”

MCI hopes that TV watchers will find such a friend in the company’s new technology. Called networkMCI Business, it is designed to allow companies to connect via personal computer to the Information Superhighway. To promote it, MCI knew it would need to demystify the product for the casual user. The result was a campaign, developed by a creative team from the ad agency Messner Vetere Berger McNamee Schmetterer, which featured ordinary folks. “We needed to show that our product was for real people, not just guys with pocket protectors and their glasses taped up,” says MCI executive Timothy F. Price.

Within six weeks the team gave life to the characters who would tell their story: the perky receptionist Darlene, an office Lothario dubbed Curtis “The Curt-Man” Bruno and an aging technophobe named Martin, who at first resists, then embraces, the Information Age. The idea, says Price: “If we can win over Martin, we can win over all of America.”

Just how well does melodrama move product? In Burger King’s case, not very well. A 1985 series based on a character named Herb, who hadn’t tasted a BK burger, was regarded as a flop. Just the same, some marketers insist soap ads have been successful at getting people to stop zapping commercials. Others, like New England Tel, say the spots have had a noticeable effect on the bottom line. During the three years that the company’s ads aired, phone traffic in its calling area increased 10 to 12 percent a year, a rise company executives attribute directly to the serial campaigns. They say one New England doctor who was estranged from his daughter even called to thank the company for prompting a reconciliation.

Officials at Nestle, makers of Taster’s Choice, credit their mini-soaps with increasing the company’s market share – in a flat market, no less. The ads have also boosted the public’s awareness of the brand. According to Video Storyboard Tests, which measures the popularity of ad campaigns, Taster’s Choice commercials regularly rank in the top-20 most-remembered ads on the air. Similarly, Nabisco credits its Cookie Man commercials with helping SnackWell’s become a $400 million brand in two years, surpassing even the Oreo and Ritz lines. MCI, meanwhile, has been swamped with inquiries about its new offerings. Says Price: “At this rate, we’ll be taking tens of thousands of orders in the next 60 days.”

The new commercials are even spawning their own promotional spinoffs. Nestle has solicited viewer participation in its soap by installing a phone line over which customers can vote on the names, ages and professions of the Taster’s Choice couple. (The winning choices were Michael, a 37-year-old architect, for the gentleman, and Cassandra, a 37-year-old fashion-magazine editor, for the lady, never mind that a college-age son shows up on her doorstep in the latest episode.) MCI has been approached about creating a book version of Gramercy Press. And, as of next month, fans will be able to send electronic messages over the Internet to their favorite Gramercy Press characters, who promise to answer each one. After all, says Messner agency head Bob Schmetterer, “anything is possible in cyberspace.” And, he might add, in advertising.