Every event starts out as one to benefit the attendees Not so sure. Events like Dreamforce and other company-branded and sponsored events seem to have started

Every event starts out as one to benefit the attendees Not so sure. Events like Dreamforce and other company-branded and sponsored events seem to have started with the goal of making more money/selling more stuff, and then had to go figure out how to make it look appealing enough that people would attend. (Though I still don't really know why anyone would attend Dreamforce.)