Amazon Book Marketing: Calculating a CPC That Won’t Burn Your Cash

If you’re not careful, managing your own book-advertising campaign is basically setting money on fire.

Whether you’re a self-published or “traditional” author, you know that advertising is potentially a huge factor in book sales.

Sure, some books have become bestsellers purely though word-of-mouth and a little luck; the first example that comes to mind is “The Martian,” which became a monster hit after its author, Andy Weir, started publishing chapters online. But the odds of that sort of thing happening are astronomical, up there with being struck by lightning twice in the same day.

The lieu of winning the karma lottery, a number of authors — especially self-published ones — decide the best route to visibility is buying ads on Facebook, Amazon, and even Google. On the surface, that’s not a bad idea: all those platforms are designed to put content in front of highly targeted audiences.

However, advertising on these platforms comes with a couple of huge challenges. First, you need to design ads that work. Next, you need to make sure those advertisements actually earn you money instead of burning it. For the purposes of this article, we’re going to focus on Amazon, which a lot of authors use to promote as well as sell their books. (In a previous article, I did a rundown of Amazon e-book marketing tools that analyzes countdown deals, etc.)

Trying to Hit the Right CPC

Amazon’s book-advertising system sprinkles ads throughout its book pages. If you search for a particular title, and click on its page, you’ll see an ad in the right rail, beneath the usual box with the pricing info. There’s also the Sponsored Products widgets, which display in search results and on product detail pages.

Amazon auctions off these ad spaces; if you want to win those bids, you’ll need to set a sufficiently high cost-per-click (CPC). And therein lies the issue: set your CPC too high, and your book’s ad will get a lot of visibility — but you’ll burn through the money set aside for your campaign long before you earn back the equivalent in book sales. Set it too low, and nobody will ever see your ad.

In theory, if you had a book series to promote and a lot of money to burn, you could run an ad for the first book in your series with a ridiculously high CPC, and bet that any…