Just to throw another number out there, OSB last year had around 1650 individual entrants. Of course we have to keep in mind, 1 pro can dance with a half dozen or more students, so number of entrants doesn't quite give as good a number for comparison either. A somewhat better statistic might be number of partnerships, which is not tracked anywhere I'm aware of (if only I could get my grubby hands on some comp databases). As a competitor, the only metric that matters to me is how many couples are in my category. As a spectator, it's a mix of how many couples I know, and how many top couples are present that matters. For instance, I like to go to small local comps because I get to watch people I know, even if my event is uncontested, and if a few of my favorite pros are present, it's a bonus!