NEW YORK • The drop in live television sports ratings may be more than a fumble.
Fewer Americans tuned in to both the US Open tennis and the Olympics.
Watching American football, the nation's most popular sporting pastime, is suffering too, putting nearly US$3 billion (S$4.13 billion) of advertising revenue at risk for the likes of the NBC network.
With games available in other places like Twitter, the networks are facing a tough battle.
It is received wisdom among TV executives that airing live sports events is the best way to pump up viewing figures.
No other sports franchise has managed this better than the National Football League (NFL).
NBC, CBS, Fox and ESPN collectively paid the NFL nearly US$5 billion for this season's sports rights, a 9 per cent increase from last year's season, reckon Jefferies analysts.
In turn the commercials during games are the most expensive on TV, costing more than US$500,000 on average, Jefferies estimates.
Yet, viewing figures have declined by an average of 8 per cent a week since the season kicked off last month. Adults between the ages of 18 and 34 watching a football game during the period dropped by 13 per cent, according to UBS.
Advertisers will expect to be compensated for the shortfall in ratings, meaning networks will have to give brands additional TV air time to make up for the difference between expected and actual viewers.
The weaker ratings could, of course, be an anomaly.
After all, the US presidential election race is proving to be the most calamitously entertaining ever, and that is reflected in viewing data too: the televised first debate between Hillary Clinton and Donald Trump attracted a record of more than 80 million people, trouncing the football game aired that same night.
But football is not the only sport suffering.
Some 47 per cent fewer people turned on the US Open men's final last month, compared with last year, while viewing figures for the Olympics fell 15 per cent from four years ago.
Part of the decline stems from the growth in new ways to watch television, be that using Yahoo or streaming boxes like Roku.