Letter (Astounding, April 1941): The Perfect Rating Method Is Yet to be Devised. For One Thing, How Many Readers Does One Letter Represent? Some Group-Types Tend to Write in More Than Others.
From Author Wars - https://authorwars.com/books/letter-astounding-april-1941-the-perfect-rating-method-is-yet-to-be-devised-for-one-thing-how-many-r-3395875.html
Overview:
Editions/Publications:
- Unknown. Astounding Science-Fiction, April 1941 (Unknown, Verniaud, Street & Smith Publications, Inc., $0.20, 164 pages, pulp, MAGAZINE)