"Buy Instagram Followers – Real & Cheap," the ad at the top of the Google search result declared.
What made the message so eye-catching was the way it was displayed – not in the intimate, closed confines of a smartphone screen but in giant letters on a high-definition, electronic board 10 metres wide on a stage.
Keith Weed, president of the Advertising Association and recently retired Unilever marketing boss, used the image in his presentation to the Lead conference in London earlier this year to illustrate a simple point about trust in advertising: there must not be different standards for ads just because they appear online.
All brand messaging needs to be held to the highest standards, as if every message is being broadcast in the most public, attention-seeking manner on national TV or an out-of-home billboard.
Led By Donkeys, the pro-European Union campaigning group, has used the same logic as Weed and exploited it brilliantly, by republishing old tweets and comments by Brexit-supporting politicians on 96-sheet poster sites to highlight the inconsistency of their views over time – much to the embarrassment of the Leavers.
Nothing beats the power of public media to get out a message. It is why the eco-protestors from Extinction Rebellion took over Oxford Circus, with a big, pink boat in tow, in the heart of a central London, rather than just running an online or direct mail campaign.
Recognising the differences between public media, which is available for all to see, and private media, which is tailored and targeted, is not a new debate in advertising and marketing circles.
The late Stephen King, J Walter Thompson’s planning guru, first came up with the distinction, according to Jeremy Bullmore, the veteran sage of WPP.
But the tension between public media and private media has taken on fresh relevance as the ad industry and wider society grapple with the perils of digital and social media.
Many of the smartest brains believe passionately that the future of advertising is personalised, one-to-one marketing at scale – and there is no doubt that targeting relevant, customised messages can be effective at driving efficiencies and business performance. That is the rationale for Publicis Groupe’s planned acquisition of data business Epsilon and Interpublic’s purchase of Acxiom.
Personalisation also opens up new, exciting creative possibilities. Kate Stanners, global chief creative officer and chairman of Saatchi & Saatchi, told Publicis Groupe’s investor day last year: "As a creative person, you spend your time defining and refining constantly to get to that one perfect answer but what I am relearning is there is no one answer. There are many rights. And that is quite transformational."
However, personalised advertising comes with major and growing risks, too.
Even if it does not feel creepy, it can create filter bubbles and it is harder to generate fame and social currency. Worse still, we have seen rogue actors use the digital media ecosystem to spread fake news as well as hateful and illegal content.
It’s a problem that Mark Zuckerberg, chief executive of Facebook, has finally acknowledged as he wrestles with how much social media should be public media. Facebook and Instagram have been "the digital equivalent of a town square" and they need to become more like "the digital equivalent of a living room" because "people increasingly also want to connect privately", he says.
For Zuckerberg, the future of social media, at least, is about being more private, even if a public element remains essential.
The question for marketers is how much they believe the centre of gravity is moving from public media towards private media – and whether advertising belongs there.
The answer is nuanced. But for all of us who believe in advertising’s ability to build brands, to create stature and fame and to increase favourability and trust, there should be no doubt about the enduring importance of public media.