Even by the standards of a cold rejection letter, the one Jacqueline Susann received from publishers Geis Associates in 1965 was brutal.

Her novel Valley of the Dolls was dismissed as "painfully dull, inept, clumsy, undisciplined, rambling and thoroughly amateurish". So how did such a poor book go on to be registered in The Guinness Book of World Records in the late Sixties as the world's most popular novel? The success of Valley of the Dolls – to date more than 30 million copies have been sold worldwide – is a tale of one of the most tenacious and sharp-eyed publishing campaigns of all time.

The novel, which is about the sex lives and addiction problems of four Hollywood "glamour girls", is 50 years old on February 10, 2016. The “dolls” in the title are the "uppers" and "downers" Susann's characters swallow to cope with their soap-opera lives.

Susann, the daughter of a portrait painter and teacher, was born in Philadelphia in 1918. She was at heart a pragmatist and told friends that, as she had spent 18 months writing the book, "the least I can do is spend three months promoting it". In fact, her campaign to publicise Valley of the Dolls lasted more than a year, and was organised like a military campaign.