Yet another great pulp paperback cover, for The Fountainhead (aka "The Sensational Bestseller of a Man and Woman Who Defied the World!"):
http://praxeology.net/roarkpb.jpg

There was a New York Times article from 1995 by Julie Lasky that discussed this cover:

And so it was that dozens of classic novels appeared in packages that were cartoonish, sordid or merely absurd. George Orwell's "Nineteen Eighty-four" assumed its paperback life in 1950 as a tale of "Forbidden Love ... Fear ... Betrayal.".... Borrowing a trick from mystery novels (in 1950, 26 percent of all paperbacks published were mysteries), Alan Harmon, the artist of "Nineteen Eighty-four," scattered details of the narrative across the cover like clues. There's Big Brother and the Ministry of Truth, the red sashes of the Anti-Sex League, anomie, "forbidden love," "fear," etc. And as with all good mysteries, there's a red herring. What with the triceps and leers of these characters, the cherry lipstick and mascara, the proletarian, neutering clothes refashioned as catsuits unzipped to the waist, readers might be surprised that Winston Smith and Julia were destined not for a rumble but for a brainwashing.

Another great pulp cover for an un-pulpish book: Kurt Vonnegut's Player Piano, which is even given a pulpy title, Utopia 14:
http://www.fantasticfiction.co.uk/images/n0/n3378.jpg

A Prince Rupert's drop also plays a role in Fritz Leiber's novel Conjure Wife.