Where were you while we were getting high?

How do you measure the size of a fandom? In the debates sparked by the recent fannish migration to the Merlin fandom, there were again talk about fandoms that eat other fandoms. Now I don't think anyone would doubt Harry Potter was one of those. And maybe Star Wars, Lord of the Rings and Smallville. But what about other fandoms, perhaps medium-sized ones? Do you measure them in terms of the sheer number of fics/art/crafts/fanmixes/podfics produced? The number of people registered for a fandom-specific discussion board/joined a fandom-specific community or the proportion it takes up in multi-fandom venues? The number of discussion posts? Does the quality of the fics or posts count? There are loads of lurkers in fandom, do they count, and if yes, how do they count?

I know it's stupid to obsess about the size of a fandom when, I guess, the only reason it would matter is for justifying why you're writing about that fandom in an academic paper. But I just can't get it out of my head.

I've stopped and started with this idea but never found the time to do a thorough research or flesh out my idea. So I thought I'd just write it down now or else I'll fuck up again at work (I've just sent an invitation email to 30-odd people with the subject line "Draft invitation email") because of my preoccupation with this.

The thought first struck me when watching Slumdog Millionaire because Salim and Jamal were quite a lot like Nathan and Peter (a pragmatic vs a dreamer) and also quite a lot like Dean and Sam. Then I went through a list of memorable brothers on film and TV: Lincoln and Michael (Prison Break), Del-boy and Rodney (Only Fools and Horses), Edward and Alphonse (Fullmetal Alchemist)...

It seems that more often than not the older brother acts as a sort of surrogate parent to the younger one rather than the competitor relationship that seems more common in real life. While it's very real for a close relationship to flourish between brothers who are orphaned or have parents who are so distant they might as well not be there, I cannot but wonder: Is it really so hard to write a supportive brotherly relationship without taking the parents away? Is it really so hard to write ordinary siblings at all?

OMG, OMG, OMG... John Glover! I haven't been so excited about this show for months!