Growing up, there are a few golden rules most parents lay down about strangers. Don't get in a car with a stranger. Don't touch a stranger's dog. Don't accept sweets from strangers.
What we all learned was pretty clear: don't trust people you don't know.
It's fair to say then that the idea of a sharing economy goes against all our intuitions. Nowhere is that more true than here in the UK -- most of us struggle to share a joke on a train with a stranger, never mind a room in our flat.
But these days, we're offering up our homes, cars, pets and power drills with anyone and everyone. Airbnb, Lyft, Uber, BlaBlaCar, DogVacay and Streetbank are just a handful of the companies that sit under the broad (and often ambiguous) sharing economy umbrella - all make us take that leap of faith with someone we don't know, and all have enjoyed significant success.
There are a couple of underlying reasons why these businesses work.
Price is a certainly one. I enjoy an 'all you can eat' hotel buffet breakfast as much as the next man, but if there's an Airbnb down the street for half the price, I'll probably just stay there and bring my own Weetabix.
Sharing stuff has become fashionable, too. It's the same mentality that's seen second-hand morph into vintage. Whatever the socio-economic reasons driving this cultural change, the brands that have brought us the sharing economy are reaping the benefits -- getting an Uber back to your AirBnb on a city break in Berlin is as desirable as it is affordable.
But while price and cool have been enough to win over the hearts and wallets of millions of first-time users, the sharing economy has had to navigate a much bigger issue to keep us coming back for more.
That issue is trust.
Trust in the people you're sharing with, lending to, or borrowing from is what makes this economy work. And the more that trust grows, the more we trust the brands that are facilitating the sharing, too.
At the heart of it, the sharing economy is putting emphasis back on face-to-face engagements and real relationships between businesses and their customers. It's here that real trust can be earned, and where the sharing economy has a clear competitive advantage.
It's an advantage that comes at a cost, though. Business models in the sharing economy are, by their nature, high risk. You're relying on the thousands of people in your community to represent your business and keep your customers happy. When it's working, these communities are the businesses' greatest assets. When it doesn't work, these communities can breakdown trust in seconds.
At the moment, when things go wrong, it pans out a little bit like this. You get in a scrap with your Uber driver or your Airbnb host, lose some money, take a hit on your customer rating and probably your dignity too. Five minutes later you send a strongly worded complaint to the HQ in Silicon Valley, and an over-qualified Harvard graduate responds instantaneously with some charming rhetoric and a full re-fund. All sorted. All forgiven.
But is it? Just how many of these episodes are we willing to put up with before trust breaks down irreversibly? When things go wrong, these businesses have got really good at sweeping things under the carpet. This approach will only work for so long.
The long-term answer for the sharing economy isn't more of the same. To build meaningful, sustainable relationships with customers, these companies need to build genuine trust, not get better at saying sorry. They need to put the customer experience first. Fundamentally, they need to exert greater control over their communities, with stricter vetting and responsible growth strategies.
Most of us are in agreement that the sharing economy is a good thing, for business and for society. Having trust in the people around us is usually a decent sign that things are going well, and the economic and environmental benefits are clear, too.
But the so-called 'disrupters' mustn't sit still. They've earned our trust. The bigger challenge now is to keep it.