It's standing room only and for non "in demand" games, the Mets suck and there's way too many games, especially weekday games. Hell, I don't even think it's that great of a deal when you can look at stubhub and grab seats for $6 for the vast majority of home games anyway that aren't "in demand" and go stand wherever anyway.
I still say it's going the other way, it's working in the NFL and MLS, some MLB and college teams too and more teams are doing it every year. I have full season tickets and never buy anything from the concessions for the Devils or Red Bulls at the moment...
In Atlanta, Concessions Prices Go Down and Revenue Goes Up