Plain Vanilla Games, the studio behind the wildly popular QuizUp, a trivia app for iPhone, announced today it has raised a $22 million series B round of venture capital funding. Since it launched only five weeks ago, the game has already racked up more than 5 million downloads. Perhaps most importantly for the app's long-term prospects, more than 22,000 users have applied to become Wikipedia-style contributors to the topic forums created around trivia categories like basketball, horror movies, and theoretical physics.

"There is always a danger with games that people play them for a week or so, then get bored, discard them and move on to the shiny new thing," says Plain Vanilla CEO Thor Fridriksson. The company had that experience with its first game, The Moogies, launched in November of 2011. It sold well, was highlighted by Apple, and then dropped off the charts once it was no longer featured. "The difference with QuizUp is that our users are becoming part of communities, chatting with one another, forming relationships, and investing deeply in the experience."

"There is always a danger with games that people play them for a week or so, then get bored."

Plain Vanilla has three goals for its new funding. "The first is to expand to additional platforms like Android and iPad," says Roelof Botha, the partner at Sequoia Capital who led this investment round. "The second is to expand into additional languages beyond English. And lastly the aim is to create more localized categories, so that people from say, South Africa, where I am from, can begin to create trivia about local sports like rugby and cricket that don't yet exist." Having the cash to fuel this kind of expansion will certainly help QuizUp find a new audience, although it doesn't guarantee the game will have long-term appeal.

QuizUp lets users pay for experience points that can be exchanged for trophies or used to customize players' profiles. It has plans to monetize by letting companies sponsor certain topics, something it had great success with when promoting films like Twilight and Batman. "It gets fans of the franchises engaged in a very natural way," says Fridriksson.

QuizUp did experience a security snafu which the company says it has now addressed. And over the Christmas holiday it plummeted down the App Store charts, falling from the top 10 as low as number 22, likely because new iPhone owners were busy installing loads of big-name mus- haves like Instagram, Snapchat, and YouTube. The question now is whether it can regain its top spot alongside titans like Candy Crush and execute on its expansion plan with new funding in hand.