How to write a book blurb that sells the story

Open a bestseller list and read the back-cover copy on any book you already love. Notice what it never does. It doesn't summarize the plot from start to finish, and it doesn't explain how the story resolves. It sells you a single unanswered question, and answering that question is the entire job of a blurb.

Most unpublished writers get this backward. They treat the blurb as a book report, cataloguing the setup and walking through what happens next. A reader who wanted a plot summary would read the Wikipedia page instead. What they want from a blurb is a reason to spend the next eight hours with your characters instead of someone else's.

What a blurb actually has to do

A blurb has one purpose: convince a stranger to read your first page. It is not a synopsis. It is not a query letter, which is a different document written for agents and editors, with its own rules about comparable titles and word count. A blurb compresses your book down to the exact moment a browsing reader decides they need to know what happens next. Subplot and secondary characters get cut, because neither one does that job.

This is why blurbs fail even when the book behind them is strong. You know the manuscript intimately, so it's hard to tell which details matter to a stranger meeting your story for the first time. Every scene in the book matters to you. Almost none of them belong in the blurb.

A structure that works

The formula that shows up again and again in successful trade fiction isn't complicated. It gives a reader a person and breaks that person's world open. Then it stops just short of telling them what happens next.

Paragraph 1: the ordinary world
  Who is the protagonist? What do they want, and what does
  their life look like before the story starts?

Paragraph 2: the disruption
  What event forces a choice they can't avoid? Name the
  conflict directly instead of gesturing at danger or secrets.

Paragraph 3: the stakes
  What happens if they fail? End on the question this raises,
  not the answer.

Notice that nothing in that structure asks you to describe how the story ends. It asks you to describe a person under pressure, then leave the reader standing at the edge of finding out what that pressure does to them.

Where blurbs go wrong

• The blurb explains too much of the plot, so curiosity has nowhere left to go
• It introduces four or five names with equal weight, and none of them becomes a person the reader can hold onto
• It leans on mood and atmosphere instead of naming an actual conflict
• It opens with world-building or backstory instead of the person the reader is about to follow

Match the blurb's voice to the genre

A thriller blurb should move the way the book does: short sentences and danger named early. A romance blurb needs to name the tension between its two leads in the first two lines, not several paragraphs in, because that tension is what readers of the genre are actually buying. Get the voice wrong and you've told a genre reader, before they've opened the book, that what's inside won't match what they came for.

Rewrite until it stops summarizing

Compare two versions of the same premise.

Before

Sarah has always dreamed of becoming a doctor. When her mother falls ill, she has to balance medical school with caring for her family while starting a new relationship. Will she manage to have it all?

After

Sarah is eleven credits from her medical degree when her mother's diagnosis arrives. She built her adult life on the belief that ambition and loyalty don't have to compete. Now she has six weeks to prove it, or watch the family that raised her come apart while she finishes what she started for them.

The first asks a question so soft it barely counts as one. The second gives the character a deadline and something to lose in the same breath. That's the difference between a blurb that reports and a blurb that sells.

Writers pad their blurbs with subplot for a simple reason: working from a manuscript held one scene at a time in your head makes every scene feel load-bearing. Chaptered's corkboard view lays the whole manuscript out as cards, side by side, which makes it much easier to spot the two or three beats that actually carry the central conflict, the ones your blurb needs, before you write a single line of jacket copy.