The conventions of mockumentaries ensure that the pacing of the jokes is fairly slow. The humor usually requires that the characters be quirky and dense beyond all reason, but somehow seem real and recognizable. This puts a premium on a highly nuanced line delivery. Guest is ok at this, but he can't seem to get it to really take off and fly. Fred Willard and Caherine O'Hara, as noted in a post above, are true masters at it.
― Aimless, Sunday, 19 May 2013 18:09 (ten years ago) link