You arrive at the event venue and are directed to your table. Your new books are already placed in boxes under your table. You hang up your poster and drape your tablecloth, then set a stack of books on the table and label it with prices.
You sell your books and have a great time chatting with your fandom friends!
At the end of the day, you have some books left over. You walk over to the Toranoana representative and fill out a form, and they take your books for consignment sale.
You go with your friends to the afterparty and get drunk while talking about the thing you’re into.
Much later, you post the contents of your book on the internet to be read for free. This is usually done when the book has completely sold out or a year has passed from the original event.

I’m sorry for the unmitigated infodump. There’s just no short way for me to say that these events rock.