Valley of the Dolls (idea)

The title of the novel allegedly refers to author Jacqueline Susann's drug of choice and favourite method of taking said drug.

Let me explain;

1. barbiturates are barbies hence barbie dolls or dolls
2. Jacqueline Susann's favoured method of ingesting (if that's the right word) was by means of an anal suppository

I strongly suspect that Jacqueline Susann failed to explain this to her publisher prior to publication of the novel.

I say allegedly only because this is what I remember reading a few years back in a newspaper article written about the novel (it was the 25th or 30th anniversary of its publication or something) and can't quote any definitive source. But to the best of my recollection this where she got the title from.