I often see indie and self-published authors on social media reinforce the idea that a cruddy book cover doesn’t necessarily mean a book is terrible. And that much is true. But while an unappealing cover might not represent the quality of the book, it will certainly prevent readers from buying it.

The first thing a reader is going to judge your book by is its cover—not because your book isn’t great but because of how people make buying decisions.

 “For the last 50 or 60 years, market research, as an industry, has believed that people make decisions based on rational, conscious thought processes,” writes Peep Laja in Purchase Decisions: 9 Things to Know About Influencing Customers. “Science tells a different story, one that turns that fundamental belief on its head. Most decision-making happens at the subconscious level . . . we may focus on facts and numbers, but in many cases, it’s the subliminal that makes people decide one way or another.”

If your cover doesn’t stand out, you don’t have a chance.

Grabbing—and holding—a reader’s attention

“The browsing stage of the buying experience is a tricky one to understand,” writes Nicole Mulvaney in Why You Bought That Book: The Psychology Behind Book Hunting. “It happens so fast. You see a book, you pick it up. Why? What was it that caught your eye?”

The first thing to understand when discussing the psychology of book sales is that the human brain evolved in order to make immediate split-second decisions about things.

The cover isn’t actually the sales tool; it’s a way to capture the reader’s attention long enough that they turn over the book and read the book copy. Or they might even begin by flipping open the book and taking a quick scan to determine your writing style. The cover is merely the shiny wrapping designed to get customers in the door.

Perception is everything

Your book cover does not indicate the quality of the writing. But perception can work against your readers.

For one, there is a general assumption that if you have a terrible book cover, it’s likely your book isn’t well written. The reader will assume that you, as the author, couldn’t afford a better cover or a designer. They’ll assume your book wasn’t good enough to be published by a larger book publisher.

There’s also the unfair assumption that if you can’t afford a good cover, you’re clearly not selling enough books, which means the book must be awful. After all, if you can’t afford a cover, who’s to say you could afford a decent editor? And for that matter, if your cover is in poor taste, there’s an assumption that your writing must be an extension of said bad taste.

Want to grab their attention? Create a book cover that will make it impossible for a reader to determine who exactly published your book.

Using color and design to convey a message

An experienced designer or book marketer will be the first to tell you that what seems to be the simplest choices in designing your book cover can also sometimes be the most challenging. You might put together a cover and think, “Yep, that looks absolutely brilliant.” But what happens if you made the wrong choices?

The first thing you need to do is familiarize yourself with the genre you’re writing for. Each genre has its own set of rules and regulations, ranging from the colors you might select to the images, font, and even layout.

“It must be captivating, and it should offer a glimpse into the book’s content,” writes Damon Freeman in The Psychology Behind Good Book Cover Design. “It needs to catch the eye of prospective buyers. For example, an individual can associate yellow with citrus fruit or the sun, which then creates a perception of happiness. Therefore, if we want to hint that beyond the cover, a book is lighthearted, we opt for a yellow background.”

In order to make the most of your cover choices, suggests Freeman, take a look at what bestselling books similar to yours are doing with their covers. What key characteristics do the books in your genre have? How do they use color? What do they have in common with regard to art and placement? Make sure you research what works best but also explore who your ideal readers are.

“Color perceptions are determined by gender, age, and even cultural background,” Freeman writes. “For instance, in women, red might evoke warmth and excitement, while in men it might be associated with anger or power.”

Make your book stand out . . . but not too much

One of the greatest challenges when it comes to marketing is straddling that fine line between making a statement and ensuring your book looks familiar enough to feel safe.

“You want it to stand out, but not so much that it looks completely different,” advises Laja. “Essentially, the more we’re exposed to something, the more likely it is that we’ll develop a preference for it and decide to buy it.”

That sense of familiarity can be a powerful marketing tool. You want to grab your readers’ attention but also create something new and bright and game-changing. While this tactic might help you get attention, it might also be so unfamiliar that you inadvertently scare off readers.

“In markets where people have a lot of experience with the product category, it pays to mimic the market standard,” says Laja.

For most readers, the decision to buy the book is fast. Brutally fast. And one of the best ways to manage that is by ensuring your book—especially its cover—is fully optimized to take advantage.

Hannah Guy lives in Toronto and is a professional writer and copywriter who specializes in books, books, and more books. Follow her on Twitter at @hannorg.