If you go to the cities of Asia, one thing I find striking is how much more three-dimensional their urban streets are. By this I mean that you will regularly find busy retail shops and services on the higher floors of ordinary buildings, and even in the basement. Even in our business areas, above the ground floor is usually offices at most, rarely depending on walk-by traffic. There it's commonplace. I remember being in Hong Kong and asking natives to pick a restaurant for lunch. It was not unknown to just get into an otherwise unmarked elevator and go down or up to a bustling floor or sub-ground level to find the food.
Here we really like to see things from the street. A stairway up is uninviting. People want to see inside a restaurant as they walk by, to see how it looks, how busy it is, and even what the other patrons look like. I don't know why the non-main level shops can do so well in places like Japan and China, it may just be a necessity due to the much higher urban density.
However, I have wondered if the recent drop in price for HDTV panels and cameras could make a change. Instead of a stairway with sign, imagine a closed circuit HDTV panel or two at the entrance, showing you a live view of what's up there. For a little extra money, the camera could pan. While I think a live camera is best, obviously some shops would prefer to run something more akin to an advertisement. In all cases, I would hope sound was kept to a minimum, and the screens should have a reliable light sensor and clock to know how bright to be so they are not distracting at night. Some places, such as bars and restaurants, might elect to also put their camera online as a webcam, so people can look from home to see if a restaurant is hopping or not.
(There might be some temptation to run recorded video of busy times, but I think that would annoy patrons more than it would win them, once they went up the stairs. Who wants to go to a restaurant that has to fake it?)
While this idea could start with traditional urban streets, where each building has its own stairway or elevator up to higher floors, one could imagine a neoclassical urban street which is really an urban strip mall managed as a unit. In such a building, each ground floor tenant would have to devote a section of their window to show the live view of their neighbour above. Though patrons would then have to head to the actual stair or elevator to get up to the second floor. It's hard to say whether it might make more sense to put the panels in a cluster by the stairs rather than with each ground level shop.
This principle could also apply to the mini-malls found in the basements of tall buildings. However, again I fear the screens going overboard and trying to be too flashy. I really think a "window" that lets you see a live scene you can't otherwise see is in the interests of all, while yet another square foot with ads is not.