This number has been quoted an nauseum. It means nothing in terms of on going sports viewing.
In the last summer Olympics gymnastics drew . In the last winter Olympics figure skating drew 25 million viewers.
Does anyone think that this shows we are becoming a country that watches gymnastics or figure skating regularly? Of course not. We watch these things because of they are an event not for the sport itself. Similarly the Superbowl has become a much bigger event than a game. Many (most?) of the viewers are people that seldom or never watch another sporting even all year.
This is a fact. Last summer, 2013, on ESPN two games were played back to back, Yankees-Orioles and Spain-Brazil (Confederations Cup), MLB scored a 1.6 overnight in a primetime slot, while the soccer game got a 1.5 in the afternoon. Same channel, same day.
Pretty much now though any USMNT home game, even the friendlies are guaranteed sellouts, that certainly wasn’t the case only a few years ago.
A lot of so-called “Soccer”-mad countries can’t even make that claim.