Tokyo
I don't expect to see stores like this
in the U.S. The chain is just starting, located at very high
pedestrian traffic points (train stations.) The stores are called
RanKing and RanQueen. The stores carry the top five selling items
(showing the ranking on the displays) in a wide range of goods from
snacks to tooth grooming to hair grooming, to booze and soft drinks.
This is only possible in Japan because the ranking data comes from another chain, Tokyu Hands. Most stores in America and the rest of the world only carry the top three or four selling items per category. Tokyu Hands has roughly five times the number of items that would be found in an American store. I counted five times as many forms of tape at Tokyu Hands as I would find in the biggest San Francisco art store or hardware superstore.
With Tokyu Hands carrying so many different items of one kind, ranking the first five makes sense and works. The rankings are updated weekly. (There was an article on this by Alice DuBois in the 4/24 NYTimes)