Exactly When Did B.O. Stop Meaning "Body Odor"?

Riddle me that, Frank Gorshin! Oops, everyone's favorite Batman villain is dead.

But riddle me this, Hit & Run readers: Why do we care about movie box office performance? Witness this article in today's Wash Post Style section Revenge of the Sith's box office coup (or semi-coup) over the weekend. Or this tally over at Movies.com.

Maybe we don't really care, but it does seem to me that there's a helluva more general attention paid to movie b.o. than, say, 20 years ago, when this sort of thing was largely confined to Variety and industry trades.

I'm not saying it's a bad thing, just an interesting thing. And I'm curious to know why we care more now.