You've seen them. The titles under a book that show you what "Customers Who Bought This Item Also Bought." Let's take a look at what they are and why they're important.
What They Are
Limited to 100 titles, the alsobots are a representative sample of just what it says: other titles customers have bought who have bought the book on the product page. They are one of Amazon's recommendation tools that help filter products for the customer. By pointing customers to other like books, alsobots help validate readers' choices. While their purpose is pretty clear, it's what "representative sample" might mean that causes the headaches.
Much of what Amazon presents a customer is based on that customer's recent viewing habits, searches, and buys, creating a tailored and unique shopping experience for each customer.
The alsobots are, however, not tailored to the customer, so what one person sees associated with a book, all customers see. In the ideal scenarios alsobots are closely associated with the book on the product page in terms of genre, rank and price.
The alsobots on the first pages are most representative of recent purchases. Amazon recalculates alsobots every 3 or 4 days keeping track of trends and, theoretically, ensuring your book tracks with like books.
What They Aren't
Alsobots are not mutually listed. Just because you have a certain title in your alsobot list does not mean that title has your book in its list. In fact, as your book is first building its list of alsobots, it may well not be listed in any other book's alsobots.
In general, don't expect a book typically ranking in the 80,000s to be in the alsobots of a book ranked in the 2000s. However, a book with a ranking in the 2000s might well be in the alsobots of a book ranked in the the 80,000s if there are no other close matches for it.
If you're looking for gatekeeping mechanisms on Amazon, the alsobot list is one of them. Unless your book is doing well to begin with, alsobots will not help launch your book into the stratosphere. Being an alsobot on page 16 of a handful of books that sell only a copy or two a month isn't going to bring in the business.
How You Get Them
If you publish a book the same day the alsobot algorithms are recrunched then you'll have to wait till they crunch again before alsobots will start to appear on your page or, more importantly, before your book starts to appear on others' alsobots. You, of course, have to sell a couple of books before they start appearing and even then, unless you have a runaway hit out the gate (and using free you possibly can have just such a hit), your alsobot list will only slowly fill in.
Trying to game the alsobot algorithms by having a lot of people purchase the #1 bestseller in your genre along with your book won't actually work. As discussed, the algorithms take into consideration price point and rank, and while your book may be in the same genre and similarly priced to the #1 BS, if it's not somewhere close to its rank, it won't be listed. What the gaming WILL do is give more visibility to the bestseller by adding it to your book's alsobot list, which in turn, makes the BS more attractive to buyers who will buy it and push its rank even farther away from your book's.
The alsobot system is publisher-blind, so it's democratic in that every book has the same theoretical chance of getting good placement. Just like every citizen of the US has the same theoretical chance of becoming president. Yeah, not going to happen without some boosting being done on the author's part first.
What Happens To Them When Your Book Goes Free
In the world of alsobots, free downloads count. Within a day or 3 of setting your book free, you'll notice a lot, if not all, of your alsobots now contain books that were free at the same time as yours. Where once the alsobots for your $4.99 dark urban fantasy were $2.99-6.99 fantasies with a handful of horror and thrillers thrown in, now you'll have 99c-$12.99 recipes, romantic comedies and books with cute kittens on the cover populating the first pages of your list.
Is this a bad thing?
Depends on who you talk to and what types of books you're selling. Remember, the alsobots on YOUR book are there to help guide readers to OTHER books. As a stepping stone along that path, it doesn't matter WHAT books are in YOUR list -- UNLESS you write series and the first alsobots in the list are your own books in the series.
With a stand-alone, your biggest concern shouldn't be what alsobots you're "stuck with" after going free; it should be how many of the books that are good matches to your book are going free and losing your book from their alsobot lists. The problem, of course, is discovering what books your book is associated with. There's a clever tool out there now that lots of people are using to try to find out. (Now that I'm looking for the link, I can't find it. Will update with the link when I run across it again.) I've tried it and, if it's an accurate picture and my books really do have so few associations on other books, then alsobots must have a lot less impact on buying behavior than what general wisdom and polls would have us believe. I'm betting on wisdom and polls in this case.
I haven't seen deep research yet into whether a book going free for a day or two causes it to lose place on other books' lists (books that don't go free). What I do have is anecdotal evidence that says they don't. This is important for authors putting up stand-alone books to know. The risk of going free seems to be less -- perhaps to the point of negligibility -- with stand-alone books than for books that are part of a series where Book 2 will no longer show up as an alsobot of Book 1 if Book 1 goes free.
Anecdotally, many books that go the free route and lose their closely associated alsobots still wind up with a better sticky ranking than they had before going free. That suggests that perhaps any concern over alsobots is unfounded for stand-alone books that go free and possibly even for series books that go free.
I'd love to hear others' results, whether after a free run in Select or for books not in Select that have had their sales affected because the titles they're associated with have gone free limiting their visibility and discoverability.