PyCon is a community conference run by volunteers, and is underwritten by the Python Software Foundation (a non-profit public charity). The PSF wants PyCon to be an accessible, affordable conference. To that end, every year PyCon is budgeted to operate at a (small) loss. But (almost) every year we have had more attendees and more sponsorship than the year before, and PyCon has always come out in the black. We're still receiving invoices and paying bills for PyCon 2008, and won't know the final results for a while yet.
Any proceeds go into the PSF's general funds and are used for the good of the community. For example, in recent years, the PSF has sponsored other conferences and events: EuroPython, PyCon UK, PyCon Italia, Jornada Python en Santa Fe (Argentina), and more.
PyCon introduced a new, higher "corporate" registration rate (the old "regular" rate was renamed to "hobbyist"), and I was pleasantly surprised by how many attendees chose the higher rate. This enabled us to be even more generous than we had planned with financial aid, among other efforts. Even at the higher rate, PyCon is a bargain.
Speakers Must Also Pay?
Some have asked why PyCon doesn't give all speakers free registration.
The consensus so far has been that in order to keep PyCon affordable for all, everyone should support the conference by paying their own way. There have been a few exceptions to this rule. Free registration was offered to invited keynote speakers and organizers. Not many took the offer, although those paying their own way were encouraged to take free registration.
When PyCon had 300-400 attendees, we couldn't afford to give free registration to 60 or more speakers. They represented a significant fraction of the attendance and PyCon's revenue. Now, with 1000+ attendees, free registration for speakers would be much easier to accept. But should it be automatic? I think we should continue to require speakers to ask individually. However, the wording in the CFP should be changed to make it clear that for speakers, waiving registration is easy.