more theory

[totient]

Every SF convention of more than 4200 people ever has been at least a 4-day con. We have no data to say, but I suspect that it's simply impossible to run a 5000-person 3-day event. It just won't fit.

Comments

[fizzixrat.livejournal.com]

The StarCon/StarFest cons in Denver were two-day cons well past when they first topped 3000 (in 1984, when DeForest Kelley was there). Last one I attended (over a decade ago) was a 2-day con with some early registration and activities on the Friday night (so call it 2 1/2 days, if you like) -- attendance was around 8000.

I think the first 3-day SF con I attended was Chicago TARDIS in 2003, and they only had an attendance of about 400.