But Cooney and Lesser and a third partner — Lloyd Morrisett of the Markle Foundation in New York — set out to try anyway. They enlisted some of the top creative minds of the period. They borrowed techniques from television commercials to teach children about numbers. They used the live animation of Saturday morning cartoons to teach lessons about learning the alphabet. They brought in celebrities to sing and dance and star in comedy sketches that taught children about the virtues of cooperation or about their own emotions. Sesame Street aimed higher and tried harder than any other children's show had, and the extraordinary thing was that it worked. Virtually every time the show's educational value has been tested — and Sesame Street has been subject to more academic scrutiny than any television show in history — it has been proved to increase the reading and learning skills of its viewers. There are few educators and child psychologists who don't believe that the show managed to spread its infectious message well beyond the homes of those who watched the show regularly. The creators of Sesame Street accomplished something extraordinary, and the story of how they did that is a marvelous illustration of the second of the rules of the Tipping Point, the Stickiness Factor. They discovered that by making small but critical adjustments in how they presented ideas to preschoolers, they could overcome television's weakness as a teaching tool and make what they had to say memorable. Sesame Street succeeded because it learned how to make television sticky.

The Law of the Few, which I talked about in the previous chapter, says that one critical factor in epidemics is the nature of the messenger. A pair of shoes or a warning or an infection or a new movie can become highly contagious and tip simply by being associated with a particular kind of person. But in all those examples, I took it as given that the message itself was something that could be passed on. Paul Revere started a word-of-mouth epidemic with the phrase "The British are coming." It he had instead gone on that midnight ride to tell people he was having a sale on the pewter mugs at his silversmith shop, even he, with all his enormous personal gifts, could not have galvanized the Massachusetts countryside.

Roger Horchow, likewise, taxed all his friends about the restaurant his daughter took him to, performing the first step in creating a word-of-mouth epidemic. But obviously, for that epidemic to take off, the restaurant itself had to remain a good restaurant. It had to be the kind of restaurant that made an impact on the people who ate there. In epidemics, the messenger matters: messengers are what make something spread. But the content of the message matters too. And the specific quality that a message needs to be successful is the quality of "stickiness." Is the message — or the food, or the movie, or the product — memorable? Is it so memorable, in fact, that it can create change, that it can spur someone to action?

Stickiness sounds as if it should be straightforward. When most of us want to make sure what we say is remembered, we speak with emphasis. We talk loudly, and we repeat what we have to say over and over again. Marketers feel the same way. There is a maxim in the advertising business that an advertisement has to be seen at least six times before anyone will remember it. That's a useful lesson for Coca-Cola or Nike, who has hundreds of millions of dollars to spend on marketing and can afford to saturate all forms of media with their message. But it's not all that useful for, say, a group of people trying to spark a literacy epidemic with a small budget and one hour of programming on public television. Are there smaller, subtler, easier ways to make something stick?

Consider the field of direct marketing. A company buys an ad in a magazine or sends out a direct mailing with a coupon attached that they want the reader to clip and mail back to them with a check for their product. Reaching the consumer with the message is not the hard part of direct marketing. What is difficult is getting consumers to stop, read the advertisement, remember it, and then act on it. To figure out which ads work the best, direct marketers do extensive testing. They might create a dozen different versions of the same ad and run them simultaneously in a dozen different cities and compare the response rates to each. Conventional advertisers have preconceived ideas about what makes an advertisement work: humor, splashy graphics, and a celebrity endorser. Direct marketers, by contrast, have few such preconceptions, because the number of coupons that are mailed back or the number of people who calls in on an 800 number in response to a television commercial gives them an objective, iron-clad measure of effectiveness. In the advertising world, direct marketers are the real students of stickiness, and some of the most intriguing conclusions about how to reach consumers have come from their work.

In the 1970s, for example, the legendary direct marketer Lester Wunderman had a showdown with the Madison Avenue firm McCann Erickson over the Columbia Record Club account. Columbia was then — as it is now — one of the largest mail order clubs in the world, and Wunderman had handled the company's advertising since it was formed in the 1950s. Columbia decided, however, to hire McCann Co come up with a series of television commercials to support the direct-marketing print ads that Wunderman was creating. These were not late-night commercials with a toll-free 800 number. They were standard television spots designed simply to raise awareness. Understandably, Wunderman was upset. He had handled the Columbia account for twenty years and didn't like the idea of losing even a small part of the business to a competitor. Nor was he convinced that McCann's advertising would actually do Columbia any good. To settle the issue, he proposed a test. Columbia, he said, should run a full complement of the advertising created by his firm in the local editions of TV Guide and Parade magazine in twenty-six media markets around the United States. In thirteen of those markets, McCann should be allowed to air its "awareness" television commercials. In the other thirteen, Wunderman would air his own set of television commercials. Whoever's commercials created the greatest increase in response to the local TV Guide and Parade advertising would win the whole account. Columbia agreed, and after a month they tabulated the results. Responses in Wunderman's markets were up 80 percent, compared to 19.5 percent for McCann. Wunderman had won in a rout.

The key to Wunderman's success was something he called the "treasure hunt." In every TV Guide and Parade ad, he had his art director put a little gold box in the corner of the order coupon. Then his firm wrote a series of TV commercials that told the "secret of the Gold Box," Viewers were told that if they could find the gold box in their issues of Parade and TV Guide, they could write in the name of any record on the Columbia list and get that record free. The gold box, Wunderman theorized, was a kind of trigger. It gave viewers a reason to look for the ads in TV Guide and Parade. It created a connection between the Columbia message viewers saw on television and the message they read in a magazine. The gold box, Wunderman writes, "Made the reader/viewer part of an interactive advertising system. Viewers were not just an audience but had become participants. It was like playing a game… The effectiveness of the campaign was startling. In 1977 none of Columbia's ads in its extensive magazine schedule had been profitable. In 1978, with Gold Box television support, every magazine on the schedule made a profit, an unprecedented turnaround."