Sports Curmudgeon puts some perspective on the Nats:
This [Washington, DC] is the city they describe as having been starved for baseball for the last 35 years. This is the city that has a high level of disposable income and a burgeoning metropolitan area. This is the city that sold 2.7 million tickets.
Compare that to Denver Colorado in the first year that baseball was there. Denver was vilified by these local baseball poets when it got an expansion franchise and Washington did not. But Denver sold 4.4 million tickets in its first year — and most if not all of those seats had people in them.