I don't understand what makes a fandom multifandom exchange popular. Sometimes it's a fandom that is very popular outside of exchanges, sometimes super popular fandoms are not to be found. I know the answer is that something is exchange popular if lots of people who do exchanges are into that fandom, but why those particular fandoms? All I know is that I'm really not in sync with the collective fandom id of multifandom exchanges, with the exception of yuletide, and I can't quite figure out why. I would like to be able to do more exchanges but literally nobody asks for fandoms I'm into in a lot of exchanges with cool premises. Maybe if I had a better idea of what tended to resonate with the multifandom crowd, I could find the fandoms at the intersection of something I like and something they like and do more of them.