Social media can seem like a giant canister of petrol, just waiting for a spark.
This week, the match that set fire to the whole thing — literally, in some instances — was Nike's revelation that US football player and activist Colin Kaepernick was the face of the 30th anniversary of the "Just do it" slogan.
Within 24 hours there were countless social media comments, news stories, hours of airtime — an explosion of media hype which US-based Apex Marketing Group estimated was worth about $65 million.
But among the myriad responses there was also fury, with some social media users burning their sneakers in protest at the brand's affiliation with the controversial Kaepernick.
The outrage was enough to spook investors into shaving more than $8.8 billion off Nike's market value in the immediate aftermath of the launch.
The stock price has since recovered some of that fall, and Nike's overall value is still up by about 30 per cent on what it was at the beginning of the year.
However, the jury is still out on whether the company's dive into one of the most divisive issues in the US will work.
Damon Stapleton, chief creative officer at ad agency DDB, has no doubt the campaign will reap financial rewards for Nike.
"Brands don't just do this flippantly. They would've thought this through," Stapleton says.
"They've had Colin Kaepernick on retainer for a long period of time."
The ad exec says the campaign is a reminder to modern brands that they must accept the reality that their work is likely to upset someone.
The modern era, he says, is about "conversations and discourse", and that means brands sometimes have to pick a side, or risk enduring "a little hatred". But that's not necessarily a bad thing.
"The greater danger these days is not to have a point of view as a brand," he says.
"What Nike's doing is doubling down on its followers. They might take some heat and some people might burn some shoes, but I don't think that's going to hurt them.
"A brand has always been a promise. And beyond the promise of athletic ability, Nike is making a philosophical statement about what it believes in."
This is particularly important for Nike, which recently suffered major fallout from the 'Me too' movement as a number of executives at the company departed amid accusations of sexual misconduct.
In the light of this, the controversy likely to come with the Kaepernick campaign seems worthwhile if it puts Nike on the right side of history in coming months and years.
Barnes, Catmur & Friends chief executive Paul Catmur is a local ad executive familiar with the steps of the advertising controversy tango.
Having worked on the Hell Pizza brand for years, Catmur's agency counts among its many contentious activations the macabre 2014 idea to pin actual rabbit skins to a billboard, to promote the chain's rabbit pizza.
"Controversy can be very useful, particularly if you're a challenger brand like Hell who are fighting to get heard with a fraction of their rivals' budgets," Catmur says.
While Catmur counts himself a "supporter of kneeling protests" at US football games, he stops short of showing too much admiration for Nike, saying it's important to remember it is expressing a liberal point of view that may not be shared by millions of Americans.
"Nike is crossing an awkward line," he says. "America is becoming increasingly polarised into two camps and the issues are far deeper than whether or not you think Kaepernick has been poorly treated by the NFL for his peaceful protests."
Kaepernick isn't the first controversial sports star to appear in a Nike campaign, but Catmur thinks it's difficult to compare him with those who have gone before.
"John McEnroe and Eric Cantona are one thing, but a campaign supporting a man the US President has called 'a son of a bitch' and the right wing see as a supporter of cop killers is a provocative move in today's America."
It's worth noting that controversies don't always last forever. And what seems contentious today might seem utterly mundane in the future.
Coca-Cola's iconic "I'd like to buy the world a Coke" campaign of 1971 is a good example.
At a time when the US was embroiled in the Vietnam War, widespread calls for desegregation and the horrifying Charles Manson trial, the country's biggest beverage maker released a campaign featuring a multicultural group of hippie-styled figures on a hilltop singing about harmony across the world.
It isn't hard to imagine the pundits and columnists of the time furiously opining on the dangers of a major brand sticking its nose into politics and glorifying dangerous hippie types.
That kind of fury can play a role in keeping an ad relevant and entrenching it into a cultural moment.
As Stapleton says, a little hatred isn't necessarily a bad thing.
But good luck keeping it at a level you're comfortable with.
Drawing the line on offensive ads
Kiwi advertisers have served up their fair share of controversial ads over the years, including the following:
Long before Hell was pinning rabbit skins to billboards, it was sending condoms to customers to promote a pizza called Lust. This stunt attracted a grand total of 685 complaints to the Advertising Standards Authority (ASA) — a record to this day — and the promotion was deemed offensive.
In 1999, Toyota attracted 120 complaints over the repeated use of the word "bugger" in an ad campaign. The ASA did not uphold the complaints, saying the ads were unlikely to cause offence.
Unhappy line dancers
In 1997, a petition from 550 people to the ASA complained that a radio ad for the Open Polytechnic slighted the line dancing community by suggesting people who didn't study would have little choice but to become paperweights — or even worse, line dancers. The ad was subsequently withdrawn.