These include 6-sheets on the slip roads and entrances of all 1350 motorway service stations in the UK, and 25,000 A3-sized posters in the washrooms of shopping centres, bars and pubs, fitness clubs and service stations.
Charlesworth reports to joint chief executive Philip Vecht, and will oversee the 18 strong team of sales people liaising with poster specialists, media agencies and clients.
He replaces Andree Coetzee, who left Admedia in January.
Admedia is expanding its sales team after winning new business. Lynx has recently used Admedia posters, stickers and drinks coasters in night clubs for its Click campaign, and T-mobile used talking posters, door and mirror stickers and bar staff T-shirts to launch its U-Fix tariff.
Vecht said: "The appointment of John is key to our strategy of expanding and restructuring the sales team. We are preparing for a massive awareness push into agencies and clients based on an ever-increasing demand for creative outdoor solutions."