Reading · All about Digital Marketing

As I am an author myself, I’m very excited to share a blog about book marketing this week! Amy Castello is the Client Success Manager for Adbassador, and when she’s not making marketing magic she’s reading, cooking ambitiously or trail running with her lovable rescue mutts Otis and Pearl. This week Amy is going to tell us all about why you should be making use of guest blog posts to promote your books, and other things of course.

Hi everyone, I’m Amy Castello from Adbassador, a marketplace for buying guest posts on trusted publisher sites. I do have a stake in this, but I’m not here to sell you our services. I pitched this article because I see authors every week missing out on a marketing channel that works well for books, yet hardly anyone is using it.

Before I dive in, I want to focus on book authors. I know many readers here are digital marketers, but book marketing has its own challenges, and paid ads for books are tough right now. If you coach authors or handle marketing for a publisher, you’ll still find this helpful.

Most authors who pay for marketing use a mix of Amazon ads, Facebook or Instagram ads, and BookBub featured deals. These can all work. Amazon ads do well if your keyword research is strong. Facebook works if your ad creative is good. BookBub can drive sales, but only a few authors get accepted.

The issue isn’t that these channels don’t work. It’s that they all work the same way. You pay for attention, either per click or impression, and as soon as you stop paying, the traffic ends. Your book has to make sales during that short window.

Also, the cost per click keeps rising. In mid-2025, Facebook CPCs for book ads were about $0.80 to $1.80, depending on genre and country. Amazon PPC is pricey unless you target very niche keywords, so it only makes sense if you have a backlist or a series.

A guest post on a popular blog in your niche brings a different kind of traffic. Here are three key points:

First, readers visit that blog because they’re interested in the topic. If you post on a mystery review blog, everyone reading it already likes mysteries. You don’t have to pay for their attention—the blog has already earned it. Facebook ads target people based on rules, but a niche blog reaches people who are truly engaged in that genre.
Second, your guest post stays online. A good post can attract organic search traffic for months or even years. For example, in our marketplace, the average post on a DR 30+ site still gets visits 14 months after it goes live. Paid ads don’t offer that kind of long-term reach.
Third, you get a back-link. Some blogs use no follow links, but most use follow links. Either way, it’s a visible endorsement from another site. This helps your author platform, your Amazon listing, and your own website if you have one.

These numbers come from real orders, not estimates. Here’s what we found from 608 completed orders on our marketplace:

For small genre blogs (DR 10 to 30), the median price is $35 to $85. These blogs are often run by one person and have 1,000 to 5,000 monthly readers. Turnaround is usually 3 to 7 days. Many won’t accept posts that seem too promotional, so your content needs to be genuinely helpful.

Mid-size blogs (DR 30 to 55) cost $120 to $300. They have more readers and stricter editorial standards, so expect them to reject weak pitches. These blogs are often the best choice for book authors because the audience is large enough to drive sales, but the blog still cares about matching the right topics.

Large blogs (DR 55+) often charge $400 and up, sometimes into the thousands. I don’t recommend starting here as an author. The cost per interested reader is usually higher than with mid-size blogs, since you’re paying for extra authority you may not need.

If you compare these prices to what you’d pay for the same number of truly interested readers on Facebook, guest posts are usually much more cost-effective.

Most advice online about choosing guest post sites comes from SEO experts focused on link value. That’s not what you need. You want sites with readers who might actually buy your book. It’s a different filter.

What I look for when I am advising an author:

Look for real comments on posts—not just one-word replies like “great article,” but actual discussions. If the comments seem fake or automated, the readers probably are too.

Check if the blog recently posted about something similar to your book. For example, if they reviewed a thriller last month and you wrote a thriller, that’s a good match. But if the blog focuses on cozy mysteries and you wrote hard sci-fi, even a big audience won’t help—it’s the wrong fit.

Look for blogs where the author or reviewer has a clear, personal voice. These sites convert better for books. Pure SEO affiliate sites rarely work, even if their traffic numbers look good.

Here’s another tip: does the blog show book covers when mentioning books? It might seem minor, but blogs that display book covers attract readers who are looking for their next read. Blogs that only use stock photos tend to attract people who are just researching. These are very different types of readers.

I’ll keep these examples anonymous since the authors didn’t agree to be case studies. One author paid $140 for a guest post on a mid-size thriller review blog. The post was about “how I researched my villain,” with no hard sell—just a link in the author bio. Over six months, they tracked 34 book sales from that post using a UTM link. That’s about $4 per sale on a $9 ebook. At the same time, their Amazon ads were costing about $7 per sale.

The second author did the opposite. They paid $280 for a post on a much larger general-interest blog. The blog had lots of traffic, but sales were almost zero because the audience wasn’t interested in thrillers. This shows that blog size isn’t what matters most for book sales.

I’m not saying you should stop using Amazon ads or BookBub. If those work for you, keep going. But most authors I know have a few hundred dollars a month to spend, and they put it all into paid ads that keep getting more expensive. If you put just $100 to $300 a month into the right two or three blogs in your niche, you’ll usually see better results than with the same spend on paid social ads.

Most authors avoid guest posting because choosing the right blogs seems difficult. But it’s not that hard once you know what to look for. I hope the tips above make it easier.

Thank you Amy and Adbassador. Have you posted some guest blogs on sites to promote your book? Why not share links to your articles in the comments below?

Guest posting for book marketing

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