The National Football League is, by all accounts, a prosperous business at the moment, but commissioner Roger Goodell expressed concern over how the league can keep stadium attendance high in coming years.

According to The Associated Press, Goodell expressed concern that the enhanced television viewing experience could take away from ticket sales.

"Our biggest challenge going forward is how do we get people to come to our stadiums because the experience is so great at home," Goodell said on Friday. "When you turn on (a football game), you want to see a full stadium."

While television brings plenty of cash into the league, including up to $3 billion in broadcast revenues by 2022, stadium attendance did dip for three consecutive years after reaching an all-time high in 2007. It's unclear whether the league's overall attendance went up in 2011, after early reports that attendance would rebound.

ESPN's calculations did show that 2011 was the first year since 2008 that every team averaged a home stadium that was at least three-quarters full. Nine teams averaged a sellout in 2011, while Cincinnati had the league's worst attendance with 49,251 fans a game, despite earning a playoff berth. Only six teams failed to fill their stadium 90 percent or higher on average.

The television experience remains unparalleled, however, especially in times of recession when fans can tune in to NFL games for free. Nearly 60 million people tuned into last weekend's conference championship games. And the experience is expected to remain free for a long time, after the league signed recent nine-year extensions with CBS and FOX.

"People want to feel part of a group, feel like they're connected, and right now during these difficult times, they can turn on free television and watch the greatest entertainment that's out there," Goodell said. "They can forget their worries for just a few hours."