(My son adores his Minecraft Slime plushie and we collected the seller's business card so we might order more in the future.)
This applies to comics, manga, sci-fi, and fantasy too. My girl went as Sailor Saturn and posed with a Sailor Moon cosplayer for a photo.
I love this kind of thing, even though my husband bemoans hipsters and Bromies. We don't get to indulge in this kind of thing often - other than Fan Expo, the only time I'd get to wear my creeper costume would be Halloween - and even though it can be costly to attend (thank you Hasbro for sharing the "kids get in free" coupon!), I'm glad I have an outlet for my game-y interests and exhibitionist tendencies.