When thinking about comic/fantasy/sci fi conventions, most people immediatly think of costumes, and a gathering of people playing games or talking about the latest books and movies. Few people immediatly think of economic power and the impact a large convention can have on a city. But conventions have a huge economic impact on the cities they're hosted in, and on the vendors and dealers travelling around the world with booths.
In an essay for Apex Magazine, I looked at the economic forces behind conventions and the money behind the funny business of fandom.
You can read the essay here.