Much more recently, I blogged about a strange shakeup in the Amazon best-seller rankings. From the comments that followed, it appears that the Amazon algorithm wasn’t re-jiggered, and that the change had nothing to do with Amazon Prime and changes in shipping costs. Rather, the most plausible explanation seems to be, as several commenters noted, that Amazon was holding a big sale on inexpensive children’s books and that word of the sale caught fire on the Web, driving a ton of traffic (and sales) to Amazon.
One comment on the thread had nothing to do with the ranking shakeup, but instead concerned the familiar topic of reader reviews. It was written by a fellow who’d prefer to be known only as Richard, and it is really interesting:
I once did an experiment on Amazon by registering a dozen different accounts under different names and email addresses. Then I used each name to click on those “I liked this review” and “I didn’t like this review” buttons. I discovered a few interesting things.
I used a couple of the phony names to go to the top ten Amazon reviewers and systematically go through their reviews clicking mostly “I didn’t like this review” [buttons]. I didn’t realize before, but the people in the top ten are just fanatics about their reviews. They spend all their time on Amazon posting reviews and trying to cultivate positive votes. When it came to their attention that someone was giving them negative clicks each day, they grew dismayed. I got several emails to the email account set up in those names, asking what was going on and justifying the quality of their reviews. I responded that I didn’t like their reviews and had every right on a public Web site to give them negative votes. A few days later, ALL of my negative votes were removed from all the reviews of all the top ten reviewers, indicating to me that they complained to Amazon, which simply deleted all of my negative clicks.
With amusement, I noted that all of my positive clicks under that name remained visible. Apparently if I systematically dislike a group of reviewers and reviews, my votes get deleted, probably for some sort of abuse or something. But my positive votes continue to be highly valued.
Separately, I used another phony name to give lots [of] negative votes to another reviewer, just because I found his reviews pedantic and self-absorbed, and took a virtual dislike to him. After a few days, he too complained to Amazon, which promptly deleted my negative reviews (but why? my votes were cast in good faith, I really really hated his reviews, so I had every right to give them negative votes, that’s why Amazon gives us those little vote buttons in the first place). This time, I sent a note to Amazon customer service, asking why they kept deleting my negative votes but not my positive ones, and whether there is some numerical ceiling to the amount of negative votes we’re allowed to cast each day. A few days later, I got a saccharine note back advising me that Amazon values my input and my opinions and would never delete my votes, but sometimes they take a few days to tally up and appear on the Web site. If I would check back in a few days, surely my votes would register. I did so, but of course those votes never reappeared.
Anyway, after that little experiment in how the positive and negative review votes are rigged, it doesn’t surprise me at all that Amazon rigs their bestseller list.
If Richard is right, maybe the folks at Amazon read this paper by Judy Chevalier and Dina Mayzlin.