I would tend to look askance at the fan who's focussed all their activities into one area of fandom, whether it's fanzines, masquerade costuming, or conrunning. On the other hand, often the fan who's mostly known as, say, a fanzine fan, has in fact quietly helped out in a variety of other areas. So a concom has to look twice, ask around, and gather information judiciously.
Source: wiktionary