It happens only rarely - a television show popular enough to anchor 85 million people to their sofas for an hour.
The show is commanding $2 million for 30 seconds of commercial time, setting a record for a non-Super Bowl broadcast. That is four times the $500,000 cost for commercial time on a normal episode of Friends.
The National Football League's Super Bowl has long been the holy grail of advertising. During January's game, dominated by spots for beer and male impotence drugs, commercial time cost $2.3 million for 30 seconds.
But the finales of popular situation-comedies have become a television advertising phenomenon during the past decade, as the growth of cable and the Internet has continued to fragment a national audience.
"These types of opportunities where a good majority of the viewing audience will be watching a particular show at the same time are becoming rare," said David Blum, senior vice president of the Eisner Communications advertising agency in Baltimore. "It can be several years, or three or four years, before something of this magnitude pops up in the course of the regular television schedule."
The price for a spot on the Friends finale eclipses the $1.6 million gained by Seinfeld for its finale in 1998. That was a marked increased from the $500,000 per 30 seconds that the last episode of Cheers had drawn five years earlier.
The season-finale phenomenon reflects major changes that have transformed technology, media and marketing during the past generation.
On the one hand, increased cable viewership, the Internet, DVDs and commercial-zapping equipment such as TiVo have whittled the network broadcast audience. On the other hand, marketers have become more knowledgeable about creating must-watch events, often by promoting them across all the new media that now competes with network television. The Friends finale, for example, is heavily promoted on CNBC, MSNBC and nbc.com, other GE properties.
NBC began the "countdown" to the Friends finale two months ago when Lisa Kudrow's character, Phoebe, finally married. Since then, the network has aired old episodes chosen by viewer vote. Unlike typical Friends episodes, parts of the finale was filmed without a studio audience to ensure suspense.
At 8 p.m. May 6, NBC will precede the finale with an hourlong retrospective of scenes from the show about the on-and-off relationships of three men and three women. The finale follows at 9 p.m. The buildup is expected to become so ubiquitous that a cable channel, TVLand, announced last week that it plans to go dark for the hour of the finale and not try to compete.
According to Eisner, advertising heavyweights such as Unilever's Dove soap, Toyota Motor Corp., clothier Old Navy Inc., Wendy's International Inc. and Verizon Communications are expected to air commercials during the final Friends.
"It's just a huge marketing extravaganza," said Brad Agate, senior vice president and director of research for Horizon Media in New York.
The prime spots don't always guarantee a windfall for advertisers. Gardenburger, a California-based producer of vegetarian burgers, bought a coveted and expensive spot on the last Seinfeld. The spot increased visibility, but also the company's losses, eventually leading to a management shakeup.
But curtain calls for popular sitcoms, not an annual occurrence by any means, have powerful allure for advertisers because they guarantee "buzz" and an attentive audience.
A survey of 1,000 people by Eisner found that nearly everyone who plans to watch the Friends finale plans to watch the entire episode. Because the show is expected to generate parties to watch it, NBC created a party guide and party favors fans can download from its Web site.
The networks do what they can to milk these cash cows, but they can't create one every year. Rare is the series whose finale can attract people who never watched the show before.
"Viewing habits have moved toward more casual television watching," said Mark Hughes, chief executive officer of buzzmarketing.com, a Pennsylvania marketing company. "Niche media in terms of cable, the Internet and video games are taking people's attention away."
For decades, popular shows ended with little notice. When Gilligan's Island ended in 1967 after a three-year run in prime time, the finale wasn't distinct from earlier episodes. The story line about seven cruise passengers trapped on an island was finally resolved with their rescue 11 years later in a made-for-television movie.
"There was an untold notion that you didn't end a sitcom," said Robert Thompson, a media expert who heads the Center for the Study of Popular Television at Syracuse University. "If this stuff was to do well in syndication, you didn't want to spoil it by giving it an ending."
The Fugitive, a popular show from 1963 to 1967 about a doctor on the run from a false charge that he had killed his wife, is considered by television historians the first series with an actual ending. In the last episode, Dr. Richard Kimble found the one-armed murderer.
It took more than a decade before a television finale would be marketed as such.
M*A*S*H, based on a popular book and movie about a mobile army surgical hospital in the Korean War, attracted 100 million viewers to its last episode on CBS in 1983, still a television record. Because of the audience fragmentation since then, television experts don't expect it will ever be topped.
Commercials for the last M*A*S*H sold for $100,000 for 30 seconds, and that is considered the birth of the finale commercial phenomena.
"Advertisers hadn't caught on to the opportunity yet," said Frank Ginsberg, chairman of the New York advertising firm Avrett, Free & Ginsberg. "Now, they're always looking for some way to blow out sales and do something extraordinary."
After M*A*S*H, commercial time for the last episode of The Cosby Show in 1992 crept up to $200,000. A year later, the last Cheers got $500,000 for a half-minute. The finales also often were longer than typical episodes to accommodate the advertising demand.
Said Syracuse's Thompson, "Once M*A*S*H set those kinds of records, the networks realized it was big business."