I assume BlizzCon is on their financial statements. Statements which can viewed by investors. They have to legally provide the correct statements to investors.

A check of those statements would confirm the amount gained/lost on BlizzCon.

I am inclined to believe they lose money on it. If they admitted losing money in 2008, what keeps them from losing money when the event has gotten larger, required a larger building, more staff, and the talent involved (musicians, ect.) can now demand a bigger fee. DirecTV and RAYV can also demand more. You are also not counting services and products supplied on the floor. There are food and drink vendors which I am sure also get a chunk in addition to their profits from sales, and the goody bags are not all items provided free. As a ridiculous example let's say MegaBloks charges Blizzard $5 for each Thrall figure. That figure was an exclusive and won't be mass produced and sold at retail, so I can see them charging more for it. I don't remember offhand the exact number that attended BlizzCon last year, but let's assume 100,000. That's $500,000 for one item in the goody bag alone.

You provide me a link to where they said they USED TO lose money, and I would be more inclined to believe you. But since I have read them say repeatedly, each year, that they lose money, I believe them.