The real question isn't how many people attend, it's how many people are on staff. Arisia has often come out around 10% of attendees volunteering, but the actual need is mostly not linear and we have let other constraints vary our volunteer headcount above or below that number. The folk festivals I've been to didn't seem to have too many places where the volunteer labor needed depended directly on the number of people who came through the doors.
Changes in size affect Arisia more indirectly, through changes in budget, which allow us to do fancier things. For Arisia these things often cost volunteer time as well, and the real reason we want to grow our organization is so that we will be able to do all of the awesome things we can now afford. Does FRFF also add more things as they find they can afford them? Or do they do a similar number of more expensive things, in the form of getting in more expensive acts than they could have afforded before? Spending more money per timeslot wouldn't have a lot of staffing impact.
Re: Big Ops
Changes in size affect Arisia more indirectly, through changes in budget, which allow us to do fancier things. For Arisia these things often cost volunteer time as well, and the real reason we want to grow our organization is so that we will be able to do all of the awesome things we can now afford. Does FRFF also add more things as they find they can afford them? Or do they do a similar number of more expensive things, in the form of getting in more expensive acts than they could have afforded before? Spending more money per timeslot wouldn't have a lot of staffing impact.