Crowd Science named Corey J. Leibow president and chief executive officer. Most recently, he was executive in residence at Plug and Play Tech Center.

James Gross was named regional sales manager of SB Nation, a sports platform for content across all teams and sports, delivered for and by the fans.

Wiredrive hired Farah Fima as an account manager in its West coast office and Abby Morgan as a sales representative to work out of the recently launched New York office.

Carat named Sankar Patel as digital media director for its San Francisco office. Previously, Patel created and managed communications plans for brands including MINI USA, YouTube, Priceline.com and Columbia Sportswear Corporation.

Nurun elevated Jim Yang to chief strategy officer.

Pernilla Ammann, chief operating officer; Michael Ian Kaye, creative director of Mother Design; and Tom Webster, creative director of Mother Experience have been named partners in the New York office.

The Nielsen Company hired Ari Paparo and Amit Seth as executive vice presidents in its Global Media Products organization. Paparo will focus on advertiser solutions, cross-platform advertising effectiveness and online measurement products, while Seth will focus on developing products that maximize Nielsen's data.

Digitas North America has realigned its North American offices. Tony Weisman, global client lead and president of Digitas Chicago, expands his president role across the Boston and Detroit offices and Joanne Zaiac, president of New York and Stamford, CT expands her role to include Atlanta. Barbara Goose, executive vice president, has been elevated to executive director of Boston and Detroit. Kenneth Parks, senior vice president, managing director of Stamford, expands his role to include Atlanta. Lastly, Lange Taylor, vice president, Atlanta has been elevated to managing director.

Lana Urso joined adMarketplace from Betawave, where she was east coast director of sales.

Jackson Spalding added Chad Sour to its public relations team. He previously served as account executive and manager of social media at Moroch PR.