Such ads and signs are generally known in the Urbex community as 'Ghost Ads', I myself spend a lot of time hunting for them to photograph. If its OK with the OP, I would like to borrow that photo to add to the long running thread of such ads on the Derelict Places Urbex website?
Heres a link to the thread -
http://www.derelictplaces.co.uk/main...ead.php?t=7663