Fan convention

At commercial events, performers often give out autographs to the fans, sometimes in exchange for a flat appearance fee, and sometimes may perform songs that have no relevance to the shows or otherwise entertain the fans.

There is often tight security for the celebrities to protect against potentially fanatic fans.

Such features are not common at traditional science-fiction conventions, which are more oriented toward science fiction as a mode of literature, rather than toward visual media, and do not include any paid appearances by famous personalities, and maintain a less caste-like differentiation between professional and fan.

While the wearing of costumes—and even a costume competition (known as a "masquerade")—has been an occasional feature of traditional science-fiction conventions since Morojo and Forrest J Ackerman wore them during the First World Science Fiction Convention in 1939, this has never been the dominant feature of such events.

From press coverage of comic book and anime conventions has arisen the widespread image of fans' tendency to dress up as their favorite characters in elaborate costumes (known as cosplay in anime terminology) that are time-consuming and/or expensive to assemble.