An online business started by two Limerick entrepreneurs has been valued at $1 billion and ranks alongside social networking site Pinterest as one of Silicon Valley’s rising stars.

In 2008, John and Patrick Collison initially became millionaires, when they were just 17 and 19 respectively, when they sold their first company Automatic for $5million – and famously promised to "fill the fridge."

Now their latest company Stripe has been informally tipped as the the next Y Combinator company, following Dropbox and AirnB.

The Q1 'Rising Stars' identified in SecondMarket's report ranked Stripe in third place with a 391.7pc increase in watcher activity.

Stripe is based in San Francisco  aims to simplify the transction of accepting payments online.

Their website states it is a simple, developer-friendly way to accept payments online.

“We believe that enabling transactions on the web is a problem rooted in code, not finance, and we want to help put more websites in business,” the site states.

Speaking with Siliconrepublic.com last year, John Collison explained the thinking behind Stripe:

"Stripe was founded to make it easier for people to charge money online. A product we're creating for developers is to make it easy for developers who build a site to incorporate payments into that. That's what we're building.

“When you look at the iPad and how well it's doing, it has solved the payment aspect. In-app payments - you just go to buy some app, hit download and put in your password and that's it. But on the web this hasn't been solved.

“You go to a Wall Street Journal article and then you are redirected to forms and you could get rejected because your zip is incorrect and you don't have a zip. It's completely broken, when you think about it," he said.

Watch Stripe co-founder Patrick Collison, 23, talk about his start up below: