Books with rankings over 100,000 are also recalculated every day and applied with historic sales information and projections, although in the case of these books, history takes a back seat. Sales projections and trending take an active role here, which is why a book’s ranking can leap from 900,000 to 200,000 in the span of 24 hours or less. Does this mean the book has sold 700,000 copies in 24 hours? Absolutely not! What it does mean is that recent activity (i.e. purchases) for that book is trending higher than those 700,000 books it just surpassed. But, don’t get excited just yet; since the activity of those 700,000 other books range from slow to stagnant, one or two orders are sufficient to catapult a ranking.

If anyone runs across memes that give more information on the Amazon sales ranking algorithm, please pass them along? I'm still sorting through it, myself. Today, my book (currently scheduled for a late April 2006 release) spiked up from a ranking of 1 million-plus a couple days ago, to #32,935 . I guess that means that somebody bought a copy... ;)

Elonka :)

3/17/2006 Update: The book will be released on March 28 in the U.S., and April 27 in the UK.

Navigating the Amazon Sales Ranking