By Jason Notte

In a changing media landscape largely devoid of safe bets, advertisers are going all-in for the NFL. Their mixed results are perhaps the best reason for investors not to do the same when considering those sponsors' stocks.

As standard television increasingly loses the competition for eyes and time, NFL football draws rabid fans into the game. Advertisers bank on the fact that last year, 17.5 million people watched NFL broadcasts -- that's the league's second-highest total since 1989. (Only the 17.9 million-per-game draw of 2010 topped it.)

On NBC, CBS, ABC and Fox, viewership grew by 25 percent during the past decade to 19.8 million last year, according to the Nielsen Company. Audiences for those networks' prime-time offerings shrank by 21 percent to 8.1 million over the same span, with the NFL draw more than double that of sitcoms, dramas and song-and-dance competitions. Last year, 23 of the 25 most-watched shows on television were NFL games.

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Surely, getting their ads in front of that many viewers is a boon for the sponsors -- and, thus, their shareholders -- right?

In some cases, yes. But it's not always that simple.

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With all those viewers, it's easy to see why Anheuser-Busch InBev paid roughly $1 billion in 2011 to get Budweiser the NFL's official beer sponsorship formerly held by Coors Light of MolsonCoors. It's also why that company has spent $239.1 million on Super Bowl ads within the last decade, according to Kantar Media. By comparison, PepsiCo, the NFL's official soft-drink sponsor and snack sponsor through Frito-Lay, spent $174 million on big-game ads within the last decade.

The NFL's huge audience and potential returns are why USAA, Bose, Marriott shelled out for official league sponsorships last year and why Procter & Gamble added its Duracell and Tide brands, and PepsiCo added its Quaker products to an already lucrative deal with the league. For companies like Lenovo, which became the NFL's official computer supplier this year, it's a chance to grab some market share while increasing profile among couch surfers.

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Sometimes it works, sometimes it doesn't. General Motors, for example, has been the NFL's official vehicle sponsor since 2001. While its NFL ads may have helped as it emerged from bankruptcy, its NFL partnership didn't help its troubles in the mid-2000s.

For investors who want an idea of how to get into the NFL's game without setting themselves up for a loss, we look at some of the NFL's official sponsors who rode football Sundays to riches, others who've headed to ruin and others still waiting on the outcome.

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