Heck, I wrote a
VeggieTales crossover. Now *that* had a big audience!
NOT!
But I had fun with it. I knew the audience would be extremely limited but it was fun anyway and I actually got a better/bigger response than I would have thought, iirc.
So write what you want, just be prepared for a small readership if it's something a lot of people don't know.
And - I have a passing knowledge of Buffy and have read other crossovers where I didn't really know much about the universe, but recently I read one [Yvonne?] that I just couldn't get into. The writing was great etc, but there was stuff going on that I just had no frame of reference for [the whole of Sunnyvale had disappeared into a big pit?] and after I was about 1/3 through, I backed out. It just wasn't for me. I've heard Becky Bain's BB crossover [Timeless?] is excellent even if you're not very familiar with the BB universe. It can go either way. Just be prepared to limit your audience if you write about a certain other universe is all. It may be more for your own enjoyment rather than reaching mass audiences like other fics might.
Carol [who has visions of Superman in a
Space Jam type scenario]
