Goals outside your control are always harder to achieve than those that are solely dependent upon you. Thus, writing a book—as hard a project as that is to complete—is easier than successfully selling that book. Sales rely not only on the marketing efforts you put forth but also intentional actions by consumers. You can alert people you know that your book is for sale and remind them repeatedly about this, but whether they make the purchase is up to them. If you’re doing a book signing in public, you can sway potential buyers’ decision making to some degree by presenting a great-looking cover and making a compelling pitch for your work, but their choices are also beyond your control. A tough slog, right? And that’s the best possible scenario, with friends and family and people you encounter face-to-face in a situation where you have the most influence.

You can imagine, then, how hard it is to affect strangers’ buying decisions online. First, how do they even become aware of your book? Second, why would they take a chance on your work when there are numerous authors they’ve heard of whose books are also for sale (and even maybe price-discounted)?

Every new author faces the same hurdle: they lack credibility. The only way to gain this is for readers to recommend your work to others. Word-of-mouth endorsements about your book are the gifts that keep on giving for authors. This is how bestsellers are born, and it is what keeps generating sales for years or even decades for those books.

The online equivalent of word-of-mouth is book reviews. When a stranger does a search on the genre/subgenre in which your book is listed and happens to see your title and the cover among all the other options on their screen, they also see the average number of stars the book has received and how many people have reviewed it. Four or more stars and numerous reviews (twenty, fifty, or more depending on how much convincing a given individual needs) are usually enough to create credibility in readers’ minds. Hopefully they will be interested enough to click the link and read about your book and others’ comments about it. If this persuades them, they’ll make the purchase, and you’re all set to satisfy another reader. The process started, though, with the instant credibility brought about by having a compelling title, an enticing cover, and enough high ratings to keep the consumer from moving on to other candidates. It’s a three-legged stool, if you will—without the endorsements, it won’t stand. This is why you need book reviews: these online testimonials are as close as we can get to a friend telling the consumer they vouch for your work: “Try it, you’ll like it.” The more reviews you get, the more visible your book will be on those websites.

How do you get reviews? Ask for them nicely, without bullying tactics or guilt trips. When friends and family buy your book, ask them to please put a review on Amazon or at least Goodreads regardless of where they bought it. Millions of people make their buying decisions relying on the reviews found on those websites, so those are the places to go to post their endorsement. If they didn’t buy it on Amazon they can still post a review there—all it’ll lack is the “verified purchase” tag Amazon uses to indicate a book bought through them (only Amazon stockholders care about that tag and maybe not even them). If friends or family confirm they posted a review for you, be generous in expressing your gratitude.

This strategy will only get you so far, though. The secret to ongoing book sales is for strangers online to discover your work, give it a try, and share their recommendation of it. Some of those who buy your book will post a review because they want to help other people discover a great reading experience. I’m forever grateful to them for making this effort! Other readers are shy about expressing their opinions online but will respond to an incentive. This is why many of my books include an offer set forth in my Author’s Note: in return for an honest review on Amazon (it’s against their policy to require a four- or five-star review as a quid pro quo), Goodreads, or another online outlet, I provide them with an original short story that includes the characters they love. This is a bonus they cannot obtain any other way except by posting a review. If they email me a screenshot of their review or a link to it, per the instructions I lay out in my Author’s Note, I respond with profuse thanks and the exclusive short story, which I make sure is as well-written as the book itself, so they get something of real value in return for their efforts. Don’t worry—no one will ask for the bonus unless they loved the original book, so mostly five-star reviews are guaranteed. The additional high ratings this strategy garners boosts the credibility of the book. More sales and reviews follow, which helps to perpetuate the cycle.

What do you give away if you’re writing nonfiction? Offer something practical if you’ve written informational or inspirational nonfiction—a guide to further help or educate readers, a one-on-one consultation activity they will benefit from, or the like. If you’re a memoirist, provide a chapter that goes into more detail about an incident glossed over in your book or something that didn’t make the final cut due to a maximum page count you were abiding by or another limitation.

I have discovered that my books with this offer have many more reviews and far better sales than the ones where I was too lazy or uninspired to create a bonus short story. Coincidence? I don’t think so. And as a bonus to me, I now have additional fans I can add to my mailing list, with whom I share my Readers and Writers newsletters and details about upcoming books and signing events. This encourages more sales and more word-of-mouth endorsements. And the beat goes on.

Marketing your book and drumming up reviews are difficult, sometimes uncomfortable activities. They’re necessary, though, if you want readers to discover your work and tell people about it. Ultimately, our sales are driven by the whims of others and subject to the kindness of strangers. Reconcile yourself to this fact and do everything you can to start the ball rolling. May it continue forever.