Strictly speaking, a blurb is a summary, not a review. But there are other kinds of blogs, as well: descriptive. Historical. Literary.
So if I were to write a blurb on, say, the novel, Valley of the Dolls, I would probably be tempted to veer into some kind of descriptive or historical territory.
First of all, Valley of the Dolls is a roman a clef - thinly veiled fiction inspired by real life. For years, the three main female characters, and the barely subordinate fourth, were generally recognized as imitating real actresses with whom Jacqueline Susann worked. Just as important, the hothouse/almost incestuous connection between publicity departments and Hollywood is portrayed in a thoroughly detailed manner.
The three female protagonists share an apartment and parts of their lives. Anne Welles, the icy New England beauty, falls for a public relations man who ends up sleeping with another previous inhabitant, Neely O'Hara (Judy Garland echo). Neely O'Hara employs manipulation of any kind to get what and whom she wants, as does Helen Lawson (Ethel Merman echo). She is fiercely bi-polar, but that is at least partly because her managers and directors keep putting her on drugs so she can lose weight. Even Jennifer North, the most photogenic of the three lovelies (Marilyn Monroe echo, with a bit of Carol Landis thrown in), is pushed to lose weight and take drugs (which may have partly been responsible for her breast cancer, which then causes her to commit suicide because she sees that men only value her for her body, not her mind or individuality).
Dolls. Pills. Dolls - the semi-obedient women who have little choice but to let others manipulate their bodies and minds if they want to get ahead in Hollywood. Dolls - beautiful images of porcelain that break easily when someone tries to bend them past resistance.
Jacqueline Susann was involved in all phases of Hollywood production and writing, as well as publicity. She does an honest, if soap-operaish, job of demonstrating its falsity and illusions and woman-hatred. In the late 1960's, few had spoken with such frankness about the hard, nasty work of being an actress or TV star, and the contempt of male directors and managers for these "dolls" they regarded as bodies to manipulate to meet the illusory images Hollywood, a male province at the time if ever there was one, demanded.
At the time, Valley of the Dolls was considered sensational and garish. But no one said it was dishonest. It stands today as a crypto-feminist critique of the way Hollywood regarded, publicized and then smashed the talent, hopes and dreams of its actresses.