Jung, you really hit the nail on the head. The Monster Seats are a marketing gimmick. I was up there for standing room tickets once. It was awesome for BP, poor for watching a game though. They weren't built for extra revenue, they were built to market Fenway. The new seats they put behind home are really cool though. They've done some great things, but there isn't much meat left on the bone for further expansion.
Everything about going to Fenway has changed since the new ownership came on. It's not about baseball anymore, it's about the event of going to Fenway (Sweet Caroline and all the other BS).