What you need to know - 05/05/11

Renren IPO raises $743 million; Facebook is responsible for one in three display ads

Apple is rumored to be introducing over-the-air updates to its Verizon iPhones when iOS 5 is released in the fall. No word on whether the same functionality will come to AT&T phones.

Amazon is launching a new publishing imprint exclusively for romance novels: Montlake Romance.

Efficient Frontier has acquired social marketing company Context Optional for a reported $50 million.

Facebook accounted for 346 billion display ad impressions in the U.S. for the first quarter of 2011, or 31.2 percent of all impressions displayed in the quarter, according to comScore.

Craig Walker, the creator of Google Voice, has moved on and started a new organization called Firespotter Labs, which will be like an incubator for ideas.

TV/movie-lovers community Flixster has been snapped up by Warner Bros. Home Entertainment Group for an undisclosed amount.

Livestrong.com appointed Adam Bornstein as its new Editorial Director.

PowerReviews, a social commerce SaaS solutions provider, secured a $10 million round led by Four Rivers Group.

Chinese social networking website Renren went public on the New York Stock Exchange on Wednesday, raising $743 million for the Beijing-based company.

Facebook and Google are reportedly set to battle over buying Skype, whose IPO has been delayed.

Magic Piano, Smule’s anyone-can-play-piano app, launched on the iPhone for the first time and for free.