In The Eighth Stage of Fandom, Bloch describes the progression of fandom in the opening essay. The Second Stage, he says, is characterized by the fan starting to "write letters to the pro magazines commenting on the stories and urging that the editors throw out everything except Kuttner yarns." The Third Stage, however, finds the fan "sending personal letters c/o the editor to his favorite authors (outside of Kuttner, most fans seem to like Lewis Padgett, Keith Hammond, Lawrence O'Donnell, Will Garth, Hudson Hastings, Paul Edmonds and such people.)" The joke is that all of those authors were merely pseudonyms of the highly productive Henry Kuttner, often in collaboration with his equally talented wife C.L. Moore.
From Bill Lindblad's review of The Day He Died, 01.04.11