For the league, moving a team often reaps a financial reward.

In the case of St. Louis, the league was trading the country’s 21st-largest market for its second-largest. Before they even took the field in Los Angeles, the Rams doubled in value to $2.9 billion, sixth-highest in the league, according to Forbes — largely because of the prospect of the naming rights, sponsorships, ticket sales and other revenue the new stadium was expected to generate. The move helped increase the value of all franchises by 19 percent, and the owners would all receive a share of the $650 million relocation fee that the owner E. Stanley Kroenke has to pay.

Still, the N.F.L. may be a victim of its own success: For the first time, ratings for every one of the league’s major television partners declined this season.

Although the league blamed the distraction of the presidential election, analysts see deeper cracks in the league’s business model. Fantasy football, in which participants cobble together and bet on virtual teams through websites, has made younger fans more interested in individual players’ performances and less loyal to specific teams, and a lot less likely to sit for three hours in front of a television watching one game.

They certainly have a lot of options; maybe too many. The N.F.L. has media deals with CBS, NBC, ESPN, FOX, DirecTV, Verizon and on and on.

Whatever the crosswinds, where the N.F.L. might previously have taken its time weighing a team move, nowadays it seems more willing to give the green light if the relocation gives a sizable financial boon to the league, as was the case with the Los Angeles stadium.

“Getting to L.A. was a clear objective of the league,” said Irwin Raij, a lawyer at Foley & Lardner in New York who specializes in stadium deals. “Now they’ll have two teams instead of one and hope it drives revenue.”