MR. Anabolic .... I understand what you mean but You raise an interesting question when you said, " It's really all about the expo and how much fart powder and other nonsense they can sell you."
I've been to a good number of these expos and it's interesting to note that I have never seen any 'sale in which money changed hands' at any of these events.
In reality everything I've ever gotten was handed to me or thrown at me in the form of a 'sample' including T-shirts, wrist bands, supplements, gym passes, etc., etc.
And I seldom attend the actual contest any longer just because it's too damn boring unless it's held as a side event such as the 212 contest held within the expo area which you can see as you are passing by while visiting the expo booths.
And it does appear that the expos themselves are the big money makers which help support the contest itself.
Has anyone ever purchased anything at all at one of these expos?
I work the Toronto Pro Expo every year for the company I work for. We had 3 brands at the expo this year, and one of the brands sold a TON of product. The other two were mediocre sales-wise. The interest was there, the samples moved like crazy, but purchases were low for my liking. However, the one brand that did well released pb+choc and choc protein bars bars, and people went nuts for them. We sold boxes upon boxes. The other two brands only sold protein powder, bcaas, preworkouts, etc... And people weren't too keen on buying them.
In short, yes people buy product at expos. But bars, cookies, etc... seem to sell very well. Protein powders and BCAA powders, not so much.