MLB needs to protect fans at every ballpark before someone dies

It is pretty easy for the right people to get numbers on. What happened to attendance and seat purchases for the clubs that extended netting? And the NHL added netting over the glass some years ago, how did the effect attendance? Once you have that info the clubs should be able to make some models of the economic cost of netting.

More netting also has other consequences - like kids getting impromptu autographs or playing catch with players (the more netting would reduce that), fans can't interfere with the foul ball where there's netting (no more Steve Bartman incidents), players can no longer dive into the seats trying to catch foul balls (no more Derek Jeter dive heroics), etc.