Wrong on Pittsburgh, if they have a competitive team they draw very big crowds, many sell outs...This team has deep historical roots/very strong baseball town but the lack of the salary cap + bad management has led to nearly 20 losing seasons, naturally you are not going to sell out during those years...Baseball's biggest issue is that there is no salary cap and so team's like the Red Sox can just go out and buy themselves a pennant (A. Gonzalez). Broken system
Here's an interesting attendance 2011 stats:
http://espn.go.com/mlb/attendance/_/sort/homePct