And judged purely in revenue terms, we are right.

Match-day income for football clubs in England’s Premier League was down to 18 per cent of overall revenues in the 2014 to 2015 season - a proportion that will decline further with the league’s new set of broadcasting deals.

Ticketing income in the 2005 to 2008 Olympic quadrennium accounted for little more than five per cent of overall revenue generated, although strong markets in Vancouver and London drove this figure up to 15 per cent for 2009 to 2012.

With marquee events attracting huge live global television audiences, however, as well as blanket coverage in other media, including social, there are other ways in which live on-the-spot audiences have never been more important.

For one thing, the in-stadium ambiance provides an instant gauge of whether the hype that accompanies the build-up to all manner of sports events nowadays is justified: packed ranks of excited fans suggests yes; row upon row of empty seats, the contrary.

But the impact of live spectators may also be considerably more far-reaching than that.

The “performances” of supporters of Euro 2016 surprise-package Iceland, with their distinctive coordinated clapping, have beamed a positive image of this tiny nation around the globe in recent weeks.

This may turn out to be of incalculable value to the country’s tourism industry, which is developed enough to take full advantage, as well as Icelandic operators in a wide range of other sectors.

At a lower level, social media coverage of Belgian fans, who must have been hugely disappointed, applauding their Welsh counterparts out of the Pierre Mauroy Stadium in Lille last Friday night after the 3-1 victory that took Wales into the semi-finals, will give their country’s image a bit of a boost at an opportune time.

By the same token, misbehaviour by supporters of a number of teams, including Russia, Croatia and England, may be expected to have a negative impact on those countries’ respective images around the world.

Football’s popularity and tribal allegiances make it a special case; emotions are rarely as raw or as focused in Olympic crowds as at big football games.

One instance of a football-style mob reaction that I can recall came in Athens in August 2004, when the start of the men’s 200 metres final was delayed by the crowd’s chanting for Konstandinos Kenderis, their absent local hero, who had previously withdrawn from the Games in bizarre, if now well-known, circumstances, along with another Greek athlete, Ekaterini Thanou.

But this sort of thing is very much the exception.

Over coming weeks, though, at Rio 2016 and elsewhere, I can foresee a number of occasions when the reaction of sports crowds is likely to act as a sort of instant sounding-board for the state of personal, and even national, reputations.

Given the millions who will be watching on television the weight of these spontaneous judgements is not to be underestimated, whether or not the TV viewers agree with the views communicated in the actual arenas.

The first such episode may come at Lord’s cricket ground next Thursday or Friday, when Mohammad Amir, a left-arm fast bowler from Pakistan who seemed destined for greatness until jailed five years ago for his part in a conspiracy to bowl deliberate no balls, might take the new ball in the first Test between his country and England.

It is hard to predict the crowd reaction to this, but as one who argued that the original punishment was much too severe, I hope it will not be overwhelmingly negative.

To judge by video of the ball with which he bamboozled Somerset’s Peter Trego at Taunton on Monday, Amir remains as extravagantly talented as last time we saw him.

Moving on to Rio, I think audience reactions there may provide some fascinating insights into what the public thinks about the efforts of the sports authorities to tackle the many problems currently assailing them, in particular doping.

Normally of course, public manifestations of, well, anything really beyond muted patriotism and polite appreciation are the last thing one would expect from a glittering live Opening Ceremony audience.

Come August 5, though, the Maracanã’s response to announcement of the Russian team, always assuming there is a Russian team, should be well worth monitoring.

So will spectators’ reaction to Yulia Stepanova, the formerly banned Russian 800 metres runner turned whistleblower, should she make it to the start-line in the heats for the two-lap event.

Will she be given a heroine’s welcome? Or a more nuanced reception? Will the main body of the crowd even notice?

And say Aslı Çakır Alptekin, Turkey’s disgraced Olympic 1500 metres gold medallist, succeeds in efforts to have her doping ban lifted early and makes it to Rio.

Would her presence provoke a reaction, or is she too obscure a figure for most spectators to be singled out in such a way?

There may be times when observing the Rio 2016 crowds becomes almost as absorbing as the sporting events we are supposed to be watching.

Yes, ticket sales nowadays make up a smaller component of revenue than TV rights or sponsorship for some top sports businesses.

But there are plenty of other ways in which live stadium audiences continue to exercise influence and to make their presence felt.