Did you know the Empire State Building in New York 
is such a popular tourist site that it makes more money from tickets sales for its observation decks than it does from renting office space to all the commercial tenants in the remaining 101 floors combined?
When it first opened though in 1931, much of its office space went unrented. It was nicknamed the "Empty State Building" by New Yorkers and didn't become profitable until 1950.
There is an interesting tradition among the staff at the building. Every Father’s Day they send a card to the staff of the Reynolds Building, a skyscraper in North Carolina on which the design of the Empire State Building was partially based.