“My calls to big brands led to me asking for samples and raffle prizes,” Eder recalls to Fortune. “Soon, my student hall bedroom was filled with condoms from Durex, Jelly Belly jelly beans, coffee from Starbucks, Pot Noodles, and Lush soaps that made it fragrant for months after.”

At the same time, Eder was working as a brand manager for Yell, where he says he’d already worked with more than 30 brands. A business plan assignment for his degree became the perfect place to shape the concept.

So after graduating, he and his older brother—who worked at an investment bank and had his own side hustle on eBay—bootstrapped what became one of the U.K.’s defining student platforms, with a £3,000 loan.

Over 15,000 students signed up to get exclusive discount vouchers from over 200 local businesses in its first year. By year three, Student Beans had 150,000 users. And today? It’s rebranded as Pion, works with over 3,500 brands from Gymshark to Uber, and has over 5 million customers in more than 100 countries.

While Eder still holds a 35% stake in the £30-million-a-year turnover company, he walked away from day-to-day operations 10 years ago to pursue another idea: a location-based rival to LinkedIn called Causr, where you’d be able to see professionals nearby and connect.