Used from January 1949 to June 1950.
From January 1949 to roughly September or October 1949, appeared on all or nearly all comics from this publisher.
From October-ish 1949 to June 1950, appeared on all or nearly all non-romance comics, while romance comics used the "A Lovers Magazine" brand ( http://www.comics.org/brand/451/ ) instead.
Also used on the two volumes of The Golden Age of Marvel Comics reprint collections published in 1997 and 1999.