Considering Rovio has generated €50 million in revenue from Angry Birds - split between iOS sales, advertising on the free Android versions, plus t-shirts and plush toys - it was something of a surprise it's just raised $42 million in VC funding.

Of course, when you're a hot company, lots of people want a piece of you so it makes sense to sell a percentage of the company so the founders can cash out some of their hard work for hard cash.

Level up

But according to CEO Mikael Hed, the deal wasn't just about money.

"This round allows us to grow faster. Also, the investors will provide us with a significant amount of expertise in building market leading companies," he explained.

The funding round was co-led by Accel Partners (investors in Facebook, Groupon and AdMob), Skype co-founder Niklas Zennström's Atomico Ventures, and super angel fund Felicis Ventures.

As part of the investment, Niklas Zennström joins Rovio's board.

"All of our investors have strong track records in building global market leaders. That is what they will help us do," Hed added.