Speaking at Lessons from Cannes 2016, an event organised by Warc, Dom Boyd, group head of strategy at adam&eveDDB, also suggested that the campaigns' use of TV as a lead channel was crucial for creating a "cultural event" around the long-running series. (Readers can download a report of the event: What brands can learn from John Lewis' years of success.)
John Lewis has run its Christmas ads each year since 2011, and the brief – to make the retailer "the home of thoughtful gifting" – has remained the same.
"It's like being Madonna in the 1980s," Boyd told the audience. "Everyone's expecting you to have hit single after hit single. And everyone's waiting for you to fall flat on your face. It's really annoying!"
Marketing consultant Peter Field, who also presented at the event, added that the retailer's commitment to long-term brand-building over short-term success was crucial to the campaign's "awesome power".
"They kick up an extraordinary media storm each year. And it's accumulative," he added. "This is a campaign that runs in the couple of months leading up to Christmas, but it sees the brand through the entire year, and John Lewis enters the next Christmas in a stronger position."
John Lewis has also picked up many industry awards, including the IPA Effectiveness Grand Prix in 2012 and, earlier in the summer, the Cannes Creative Effectiveness Lions Grand Prix for Monty the Penguin. Judges for these awards were particularly impressed by the campaign's standout ROI of £7.98 profit for every £1 spent on advertising.
As TV-led campaigns, the John Lewis ads require a higher budget than a pure-play digital campaign. But both Boyd and Field agreed that a significant investment is required if a brand is to have a significant impact.
"They put adequate budget behind the work," Field explained. "It was around £4m in the last year. It doesn't buy a huge amount of media, but it's bought 1.2bn impressions at 0.3p per impression. You'd struggle to match that using purely digital. That's the power of TV, and the power of paid media."
For Boyd, the emotional approach and media used has been is key to the brand's success. "The TV ad is 90 seconds of emotional magic," he said. "Telly is your bomb. You can do lots with that. That creates the fame. More broadly, the way that we think about this TV ad from a planning point of view is as a way of creating a cultural event."
But, beyond cultural impact, Boyd saw the broader value of successful campaigns as moving from an advertising idea to a brand idea – resulting in organisational change.
"I'm interested in a service economy where things are connecting more: from a call centre to in-store, to an app, not just the ads," he said.
Data sourced from Warc