I'm one of those Merc, let my membership go once Subi closed it's doors taking the punt I'd be able to get a ticket to those games I wanted to go to and not be committed to go to those that looked like they were going to be rubbish.
When there's opposition supporter tickets available for $25 and lax enforcement of punters actually sitting in their allocated seats, I'm perfectly happy with how it's worked out.
Not sure I'm interested enough to do the research, I'd be more inclined to look at crowd numbers for teams' home games as a more accurate indicator.