From 1938 until 1957 he and Victor Knauth edited Omnibook Magazine, which published abridged versions of current best-sellers.

Geffen was also one of the founders of the Blue List, a daily paper that consisted entirely of advertising for municipal bonds that was later merged into Standard & Poor's, which was in turn acquired by McGraw-Hill.

He also founded a magazine for doctors, Medical World News, in 1961 and sold it to McGraw-Hill in 1966 for $17 million.

In 1968, at the age of 72, he resigned as a senior vice president at McGraw-Hill and became the principal owner and chairman of the publisher David McKay, Ltd.

Geffen died Saturday, October 11, 1980, at North Shore University Hospital in Manhasset, New York.