Marston was previously sales controller at the Daily Star and was most recently head of the strategic sales team at Yahoo!.
His role at Admedia will cover all revenue responsibilities from agencies and clients as well as growing the sales team.
Admedia currently owns 20,000 washroom posters across shopping centres, bars and pubs, motorway service stations and health and fitness clubs.
Philip Vecht, joint chief executive of Admedia, said: "Chris has a superb track record, experience and insight in the media market place. He is extremely well placed to build on our increasing portfolio of products and services and respond to our expanding client and agency requirements."
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