A blurb drawn from the manuscript, editable before it ships

Genre conventions are doing most of the work. A literary blurb withholds plot and promises a quality of attention; a thriller blurb promises a specific kind of trouble by the second sentence. Writing the wrong one for your book loses sales invisibly.

memoir. A memoir blurb is permitted to be more direct about emotional territory than fiction, and it has to answer why this life early. It ends by naming what the book is really about — which is the one place memoir blurbs may state a theme outright.

business. A business blurb leads with the reader's problem, then credibility in one line, then a concrete promise — often with bullets, which this category tolerates and fiction does not. The failure is opening with the author's biography.

childrens. A children's blurb is written for the adult buying and the child choosing, in 50–100 words, and its most important job is signalling tone and age. It should be readable aloud in the shop.

fiction. Fiction blurbs follow sub-genre formulas closely — a thriller blurb and a literary fiction blurb are structurally different documents — and the commonest error is including too much plot, which removes the reason to read.

graphic novel. A graphic novel blurb has to signal art style and tone as well as story, because readers of the form choose on both. It is usually shorter than a prose blurb, and it sits alongside interior sample pages that do much of the work.

non fiction. A non-fiction blurb makes a promise the book keeps, in the reader's language rather than yours. The failure is abstraction: a meditation on impermanence means something to the author and nothing to a browsing reader.

poetry. Poetry blurbs are short, restrained, and often carry an endorsement doing much of the work. They describe the collection's preoccupations rather than summarising poems, and overselling is more damaging here than anywhere else.

script. For a script the equivalent is a logline and a short synopsis, and they are read by people assessing hundreds. A logline is one sentence: protagonist, want, obstacle, stakes.

textbook. A textbook blurb addresses two buyers: the student wanting to pass and the lecturer choosing a set text. It states the course, the level, what is covered and what is new in this edition — plainly, because both readers are scanning.

travel. A travel blurb sells the narrator as much as the place, because the reader is choosing company for 300 pages. The failure is a blurb that could describe a guidebook to the same country.

Written from the manuscript itself, so it works for a book you uploaded as readily as one written here. Editable before it ships, like everything else.

Authors write terrible blurbs about their own books, and the reason is structural rather than a lack of skill. You know too much. You cannot see which detail is the hook because all of them feel essential, and you will not withhold the ending because you are proud of it.

Genre conventions do most of the work here and they are not interchangeable. A literary blurb withholds plot and promises a quality of attention. A thriller blurb promises a specific kind of trouble by the second sentence. A business blurb names the reader's problem in the first line. Writing the wrong one for your book loses sales invisibly — nobody tells you why they didn't buy it.

A blurb is a sales document and selling is a craft. A specialist copywriter who has sold in your category will beat this. But you will beat your own first attempt, because the hardest part is distance and this has it.