Online video advertising service Zefr has hired two new executives to lead its media sales division.

Rick Song, former executive vice president of national digital sales in the media and entertainment division of Clear Channel Communications Inc., will serve as Zefr’s global head of media solutions sales. Ex-Machinima Vice President Michael Saperstein comes on board as Zefr’s head of media sales for Eastern and Central regions, as well as Canada. Song will oversee Saperstein and the rest of the ad sales team responsible for placing YouTube ads.

Both will be based in Zefr’s New York office.

Venice-headquartered Zefr gets access to popular clips by convincing content creators, such as Hollywood film and TV studios, to keep the clips online even though they were posted without permission. Then it attaches ads to them. Because the studios own the videos, they take the lion’s share of the resulting ad revenue.

Like nearly all of the companies making money on YouTube, Zefr gives the video site’s parent company, Google Inc., a cut of the ad sales. Zefr also takes a percentage.

“Zefr is on an amazing trajectory as a leader in social video marketing solutions,” Song said in a statement. “The company is led by a team of inventive entrepreneurs with a vision to help brands and content owners identify, understand and target their biggest ‘fans’ on YouTube and beyond.”

The new hires follow a $30 million February financing round led by Institutional Venture Partners that included participation from existing investors U.S. Venture Partners, Shasta Ventures, First Round Capital and Richmond Park Partners.