A member of a forum or news group who takes on some personality in the form of something familiar or comical.
A gimmick poster typically will not reveal personal details about their selves or opinions unless it matches the persona they have created or are borrowing from.
Note: Most Gimmick Posters are multis. typically they are well known regular members of the forum or newsgroup.
You know that HomerSimpson is actually JohnDoe123 dont you? yeah, he's just another multi. JohnDoe123 is always makeing up new Gimmick Posters.