What goes in a book ad
Whether to advertise, what to spend and how to read the results are a separate question, handled in Advertising a book, honestly. This is about the thing itself: the image and the words that go in the slot you bought.
Start from the constraint, because it governs every decision that follows. Your ad appears in a feed or a results page in front of someone who was looking at something else entirely, and they will look at it for a fraction of a second before scrolling past. In that moment it has one job: say what kind of book this is and why it might be worth a reader's evening, fast enough to earn a click.
Not to summarize the plot. Not to list your awards. To categorize the book instantly, in a way that makes the right reader stop and the wrong reader keep going. An ad that gets the wrong reader to click has cost you money and produced nothing.
The image
The cover, large. In most formats the cover is the ad. It has to be legible at the size it actually renders, which is smaller than the size you are looking at while you build it. If the title vanishes and the art becomes a smudge, you are buying impressions of a colored rectangle. See The thumbnail test.
A real book object. A photograph or render of the book as a physical thing — on a table, in a hand, on a shelf — stops the scroll better than a flat cover file pasted on a background. The feed is full of flat images. A three-dimensional object with a shadow reads as a thing that exists, and it signals "book" before anyone reads a word.
Nothing that requires reading to work. The image has to land pre-literately: genre, mood, period, tone. If the viewer must read three lines to know what they are looking at, the ad is already past.
What fails
A cover shrunk to make room. Collages, quote boxes, three-panel layouts and a cover reduced to a corner thumbnail. Every element you add takes size from the one element that was working.
Small text. Anything you would not read from across a room is decoration. Two short lines at a size that survives a phone beats six lines at any size.
Five-star graphics as the main element. Stars, badges and "★★★★★ — Amazing!" as the headline sell a rating, not a book. As a small supporting element they are fine. As the thing the eye lands on first, they read as advertising, and readers have been trained to scroll past advertising.
Anything that looks like a product ad. Price flashes, arrows, "buy now" starbursts, discount banners. A book is bought as an experience someone wants to have. An ad built like a warehouse promotion gets the reflex that a warehouse promotion gets.
In the Cover Maker. Mockups render your real wrap as a physical book, so the ad image is your actual cover rather than a stock photo with a picture pasted on it, and the Social Pack turns the same cover into a vertical video and still frames. Start your cover → · about the Cover Maker
The copy
Three short pieces, in this order, and nothing else.
The genre promise. One line that tells the right reader this is their kind of book. A locked-room mystery in a snowbound hotel. A slow-burn romance between rival bakers. Not "a gripping tale of love and loss" — that describes every novel ever written and promises nothing.
A reason now. New release, out this week, book three is here, the series is complete. Without it the reader files the book under "sometime", which is where books go to be forgotten.
A plain call to action. Read the first chapter. Out now in paperback and ebook. One clear instruction, no exclamation mark required.
Comparison hooks do the work of a paragraph. "For readers of" plus two names a reader already knows communicates genre, register, pace and tone in four words, because the reader does the categorizing themselves. Pick comps that genuinely match — see Comp titles: reading the shelf you want to be on — because a comp that oversells recruits readers who will be disappointed, and they review accordingly.
No synopsis. The blurb's job is to convert someone who already clicked; see How to write a blurb that sells the book. Putting it in the ad asks a stranger to read 150 words before they have any reason to care.
Testing
Change one element at a time. A new image and new copy together produce a result you cannot attribute to either. Hold everything else and move one thing: the image, or the headline, or the comp.
Give each version enough time to mean something. A few hundred impressions is noise. Decide the period before you start, and do not call a winner on the first afternoon.
Keep the losers. Write down what you ran and what happened. Six months from now you will otherwise re-test the version you already disproved.
When the ad is not the problem
The most common failure here is not the ad at all. If the images and the copy are doing their job and the clicks are not converting, the ad is buying you a clearer view of a problem that already existed: a cover that does not fit the genre, a blurb that summarizes instead of sells, a book in the wrong category, or a price that sits wrong.
That is worth knowing. A campaign that fails on the page rather than in the feed has told you precisely where the work is, and the work is free. Fix it before you buy more traffic to the same page, because the ad multiplies whatever your listing already does, in both directions.
Make your cover
The Cover Maker is free to use: name your book, bring your artwork, and it draws the full wrap — front, spine and back — to your printer's own measurements. You only pay when you want the files without the preview watermark.
Next: Advertising a book, honestly · More: Mockups: showing a book that does not exist yet · Book trailers and short video · Genre conventions: what your cover has to promise