More than 100 million Americans are expected to watch this year's Super Bowl, but there are about 7 billion people in the rest of the world who may not be so captivated.
The NFL has a loyal following in countries including Britain, Australia, Canada and Mexico but may be struggling to gain a foothold in the prized China market, where most people do not have the "foggiest idea" of the sport.
Germany attracted large crowds during the now-defunct NFL Europe while Brazil has the infrastructure from the soccer World Cup to potentially host NFL games.
The National Football League has held games in London's Wembley Stadium since 2007 -- all three this season sold out -- and is open to the idea of establishing a franchise there.
"We're encouraged by the work we've done in London, the belief we can build long term fandom for the game way beyond a one-off experience," Mark Waller, the NFL's executive vice president of international, told Reuters.
"We believe now we can take a look at the obvious next market. We have a good fan base in Germany ... so it's a logical next focal point for us within the European market."
Bill Peterson, a former president of NFL Europe, confirms that Germany has many American football fans.
"The Frankfurt Galaxy (NFL Europe team) always had tremendous success," said Peterson. "At that time there were 2,000 American football clubs in Europe playing the game from juniors through to adults."
But Peterson acknowledges American football is a "niche" sport in Europe that will not displace soccer in popularity.
Last year's Super Bowl was watched by an estimated 160 million viewers worldwide, the bulk of which were in the United States. By comparison, the 2014 World Cup final between Germany and Argentina had a global audience of about 1 billion.
The NFL has a decent following in Australia, where last year's Super Bowl had a TV audience of 210,000, a good figure for a Monday morning in a country of 23 million.
The NFL hit the mainstream there in 2009 when Ben Graham became the first Australian to play in a Super Bowl, a feat that attracted enormous media attention Down Under.
But Australia's Asian neighbors may be a tougher market to crack, including China, the Holy Grail for international sports bodies seeking a piece of the world's second biggest economy.
Zhao Yaqing, a student at Shanghai University of International Business and Economics, is a huge fan of English Premier League soccer team Manchester United, and watches nearly all their matches live on TV or the Internet.
But she does not follow the NFL and says interest is negligible among her university friends.
"Most Chinese people don't have the foggiest idea of American football," Zhao says. "Instead, many boys in China are familiar with NBA and European soccer."
The NFL's Waller admits China is a challenge.
"The major issue for us is the enormous time zone barrier to allowing fans to engage in the game live," he says of China, though Australia is in a similar time zone.
Another challenge is the complexity of the rules.
"It's a very difficult game to explain," said Peterson, recalling his NFL Europe experience and how the league tried to promote the "Americana" aspect of the game more than the intricacies of rules and tactics.
"We deliberately hired (stadium) announcers who didn't know much more than the fans."
Added Waller: “In (Britain) we're aiming to make (NFL) aspirational and popular as a spectator sport in the belief then it will start to grow there from the ground up and we can help foster that.
"I don’t think we have any pretension we'll be as widespread or popular (there) as soccer or rugby."
(Editing by Gene Cherry)