“Marketplaces are the hardest businesses to launch,” says OnBuy founder Cas Paton. “On day one, you open your doors, and you have nothing to sell and no customers. And because you have no customers, no retailer will join you. Why would they?”

Despite these barriers, Paton has managed to turn his Bournemouth-based marketplace start-up into a genuine challenger, taking on the household names of online retail. OnBuy now boasts 11,000 brands and retailers, from Lego and Samsung to AO and Sports Direct. “We are attracting between 500 and 600 retailers a month,” Paton claims.

He launched OnBuy in November 2016 to bring further transparency and fair play to the industry. OnBuy treats all its brands and retailers equally, charging the same fees to all. It never competes with the companies listing products on its site or steer consumers toward specific products.

This approach has resonated with shoppers and brands alike. “It took 18 months to get to £100,000 in sales each month,” he says. “Then another year to get to £1m a month. After that, it was only another year before we hit £10m a month, and this is only the beginning.” The business now employs 100 staff – with 100 further roles currently advertised.

Being based in “a beautiful seaside town” has helped to attract top talent, Paton says. “Some people don’t want to be in London but still want to be involved with a high-growth start-up. And for people who want city life, we also have an office in Manchester.”

This year, the business raised £35m to ramp up its expansion both in the UK and overseas. “The other marketplaces out there are multibillion-dollar companies that have had, in some cases, a quarter of a century to optimise their product,” says Paton. “The bar is set very high, and we have to catch up rapidly. We are launching new courier integrations, a new online checkout, new search functions, all kinds of things that will deliver the table stakes expected by today’s consumer. That's a good start. Then we can become an alternative platform.”

Shoppers have been crying out for a new marketplace, he says, and are tired of the same choices. “They are just waiting for us to meet expectations first.”

Paton has always been entrepreneurial, launching his first business aged 14. He joined the Royal Navy at 17 and was selected as an officer but left to study law at university. “In the Navy, we would get up at 4am and go to bed at 11pm, so I found the pace at university very slow,” says Paton. “Slowing right down was a shock, so I decided to start my own business. By my third year, I had 27 staff.”

OnBuy is his most ambitious venture yet. “This is just the beginning,” he says. “We’ll grow 20 times over in the next few years. Nothing can slow us down now. Nothing! OnBuy is like a snowball rolling down the mountain – and this particular mountain is damn big.”