In addition to these powerful community and celebrity endorsements, Allbirds has harnessed the power of an online community, shunning the wholesale selling channels typically used by footwear brands in favour of an online direct-to-consumer model. “Footwear is typically so reliant on wholesale and bricks and mortar retail, but we thought there was a real opportunity to have a relationship with our customers and sell product direct to them online,” says Brown, describing how they changed the exact specifications of their first shoe style over 27 times based on online customer feedback.

The brand initially launched in the USA and New Zealand, then Australia and Canada, and this week has opened its first London store (their third globally after New York and San Francisco) in Covent Garden, bringing Brown back full circle to where the business started.

They have landed in London at a fortunate moment. The casualisation of fashion means the lines are being blurred between work and play, and trainers are increasingly a respectable part of many Londoners’ work uniform. “It’s a fundamental shift rather than a fashion trend,” says Brown. “I think it’s created a new kind of aesthetic, a new uniform.”

That, combined with the growing collective concern among fashion brands and their consumers regarding the industry’s environmental impact, has created a sweet spot in which brands like Allbirds can flourish.

“It’s not just about shoes,” says Brown. “It is about sustainable material innovation and really going after a problem that we thought needed solving. After the oil industry, fashion is the largest contributor to carbon emissions globally,” he continues. “There’s a real problem to solve there and we need to do it. If we can put a man on the moon we can make a pair of trainers and a t-shirt more sustainably.”