Ryan points out that is featured in Red Hat magazine in an article by Bascha Harris, revealing some of the benefits of ad-hoc over preplanned conferences:

The ability to adapt the curriculum and the schedule on-the-fly tailors the conference to whatever audience attends that day. BarCamp was able to take advantage of present experts. And the informal setting seemed to blur the line between speaker and attendee, turning sessions into discussions, adding more viewpoints and, ultimately, more robust information.

At BarCamp–like in open source development and in design thinking–the best ideas win.