First, let's be honest. It's not the half block walk that bothers the exiting subway rider, it's admitting to yourself that you don't know where you are in Manhattan, a humbling experience for a former New Yorker from New Jersey and serious humiliation for current residents. The compass decals are a small price to pay for an ego boost.
Second, the small price will end up as a negative number. Picture a tasteful Bloomingdales's logo at the tip of the East arrow when you emerge from the subway at 59th and 5th, a Caroline's on Broadway argyle marking the North Pole when you hop off at Times Square, you get the idea. The decals are revenue waiting to happen. Why stop at the subway exits? As Good As News would like to see one of these in the middle of every block in Greenwich Village. Just stick to the simple dark brown and gold color scheme and keep the ads tasteful, Mayor Bloomberg, you've got a winner on your hands.