FORTUNE — How much of the Winter Olympics in Sochi did you watch? And how — on a television, tablet, desktop computer, or phone — did you watch them?

It’s the second question that may prove more important to NBC CMCSA . The way we consume broadcast sports is evolving rapidly, but regardless of how we’ll tune in to Olympic events or highlights in 18 years, executives at “the Peacock” are confident that we will still tune in. So confident, in fact, that they spent $7.75 billion this week to extend the network’s exclusive coverage of the event until 2032.

Yes, that’s 18 years from now — though many news stories playing up the length of the deal fail to acknowledge that it’s really just a 10-year extension of NBC’s $4.38 billion contract, inked in 2011, to cover the Olympic Games through 2020. That was a four-event (Sochi, Rio, Pyeongchang, Tokyo), nine-year deal, and a record one at that — the most expensive rights deal in the history of the Olympics. The new extension, at 10 years and including six Games (three in the summer, three in the winter) and at higher cost, tops that.

But is it the longest duration sports-broadcast deal ever? The answer is no — but it’s close. In 2010, CBS and Turner Sports coughed up for a 14-year, $10.8 billion deal with NCAA to broadcast the NCAA men’s basketball tournament. That’s more years, and more money, than this NBC gambit. Last year, ESPN DIS signed an 11-year deal to show U.S. Open tennis exclusively, starting in 2015. That deal is longer than NBC’s new Olympic extension, but the cost isn’t comparable: $825 million. (Previously, CBS CBS had shown the U.S. Open since 1968; in 2011, it renewed its contract through 2014.)

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Today’s NFL broadcast contracts are just barely shorter than NBC’s Olympic extension. In 2011, NBC, Fox, and CBS all signed nine-year extensions of their NFL broadcast packages. Each network had rights through 2013, and extended those rights to 2022. The NFL was making nearly $2 billion a year, in total, from its deals with those three networks, and those fees went up with the new round of contracts. Those renewals were the longest agreements for NFL rights in television history, besting the eight-year deals that CBS, Fox, and ABC had signed for 1998 to 2005.

And there have been longer-lasting relationships than the one between NBC and the Olympic Games. CBS, for example, has been the primary broadcaster of PGA Tour events since 1970. It has shown The Masters (“A tradition like no other” is the network’s oft-repeated, hallowed slogan) every single year since 1956. (But The Masters operates only on one-year contracts.) NBC has only been the home of the Olympics since 1988 (for the Summer Games) and 2002 (for the Winter Games).

The fact that NBC was so game to own coverage of the Games until 2032 shouldn’t be a shock. Much of this is about branding and reputation; NBC sees value in being the sole network associated with them, even though it has often been a losing business proposition: the network lost $223 million on the 2010 Vancouver Games, and only broke even on the 2012 London Games. (The Sochi Games this past winter turned a profit, though a Businessweek headline jokingly called the profit “bronze at best.”)

NBC’s extension is great news for U.S. viewers because it may increase the likelihood that one of the Games between 2020 and 2032 will be in the United States. (There is currently no location set for the Games after the 2020 Winter Games in Tokyo.) Steven Cohn, the editor of Media Industry Newsletter, says that there’s no guarantee the International Olympic Committee will do NBC any favors, but the network is still likely counting on it. “Hopefully the IOC will help them out,” Cohn says. “I think it’s a pretty safe bet that one of those Games are going to be here in the U.S., either Winter or Summer in the next 15 years. But maybe not. It would be a huge help to NBC.”

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Cohn points out that the 2014 FIFA World Cup, which will take place in Rio de Janeiro, Brazil, could actually be an influence and indicator on future Olympic locations. “Rio is a good location for the World Cup because it’s closer to the Eastern time zone,” says Cohn. “But South Korea [where the 2018 Summer Games are] is not good.”

This leaves just one question: Did NBC overpay for its future Olympics coverage? It might look that way now, but there’s no way to know for sure. No one knows how we’ll watch live sporting events in eight years, much less in 18. But even if we won’t be watching on a traditional TV screen, you can bet that NBC will do whatever it has to in order to provide access to the Games on every platform, whether that means creating new and better mobile apps or catering to some entirely new device. And NBC’s bet is that the price of broadcast rights for the Olympic Games will continue to go up, and that it’s getting a better deal now than in the future. A gold-medal business decision? We’ll find out.