Mobile advertising agency Apptera has taken $10.5 million in fresh funding and has tapped a former Yahoo senior executive to join its team.

Apptera, which operates the MobileAd Xchange in-call voice advertisement network used by services such as Moviefone and Bank of America, plans to use the new cash to build both its voice and visual mobile ad platforms. The company claims to be serving “millions of ads a month, growing at a triple-digit rate.”

As for the former Yahoo man, one-time sales leader David Karnstedt will take on the role of Apptera’s board director. Karnstedt is credited with helping build Yahoo’s network of brand partnerships and direct response advertisers. Prior to his work at Yahoo, he served as an executive at Wired Digital, Alta Vista, and Overture.