Q&A: Are Amazon Sales Ranks stuck again?

QUESTION: Have you noticed a problem with Amazon Sales Ranks? In the past week I've watched "in stock" inventory levels drop without seeing my Amazon Sales Rank rise.

ANSWER: Amazon has definitely been having a problem calculating sales ranks since Thanksgiving time.

So far, I have one title available on Amazon supplied through Lightning Source. It's been available for 13 months, and over that time the sales rank averages about 5,200.

Like clockwork, the book sells about 10 copies a day, and I'm assuming at least 90 percent of the sales are on Amazon -- it's a short-discount book not carried in
brick-and-mortar stores. Around Thanksgiving, my sales rank plummeted as low as 65,000 and right now it's in a holding pattern around 25,000.

Meanwhile, the book has continued selling 10 copies a day, according to iPage, just as normal. So something at Amazon is out whack. I also track the sales ranks of about a dozen other titles in my niche, and they all look screwed up too. Usually the ranks jump around in response to sales, but they're in a holding pattern.

One more curious thing I noticed this morning: My detail page on Amazon now says: "Only 5 left in stock--order soon (more on the way)." I've never seen that notation since my book was first listed 13 months ago (before Amazon began stocking it).

Also new today on my detail page is the notation "Want it delivered Thursday, December 14? Order it in the next 4 hours and 48 minutes, and choose One-Day Shipping ..." I see that offer on most detail pages, but my impression was that it doesn't appear on the detail pages of LSI books. Here's the page.

Here's hoping that this is simply a temporary glitch at Amazon and not some policy change that undermines short-discount books.