Ads are not only used for conversion, they are also good vehicles for building brand awareness. Sometimes they're just fancy "Spite Fences"; look at the harbour

Ads are not only used for conversion, they are also good vehicles for building brand awareness. Sometimes they're just fancy "Spite Fences"; look at the harbour skyline of any major city like NYC, Hong Kong or Sydney; you will see a row of giant buildings, each with an electronic manufacturer's name (Sony, Samsung, Panasonic, Hitachi, LG, etc.) They have the appearance of "head quarters", but look close .. it's most likely a rented spot. Why do they all congregate at that corner? why not spread somewhere else? A good chunk of advertising, specially billboards, is actually "defensive" in nature.