Todd Cadley, who led Horn's New York office, has moved to publicly traded mobile ad company Millennial Media as VP of communications.
Cadley served various in-house marketing communications roles at EMC Corp. over eight years before moving to Horn in early 2012, first as senior VP and then as managing director in New York.
He oversees PR, analyst relations, social media, executive and internal communications at Millennial, which went public in 2012 and received $175M in a series E funding round in November.
Cadley reports to executive VP for global sales & operations Mollie Spilman.
Shares of Millennial, which installed a new CEO in January, are trading at the lower end of its $5.78-$10.48 range over the past year. Revenue for 2012 hit $259.2M on a net loss of $15.1M.
Max Nelson left the senior corporate communications slot at Millennial in October to lead PR for SalientMG.