Amazon's algorithm for sales ranking is complicated and some recent attempts to extrapolate the data have yielded some basic guidelines.
Discusses approximate sales from sales ranking. Here he mentions that a book needs to sell a copy a year on Amazon, through Amazon direct or a marketplace merchant, to have an approximate sales rank of 2,000,000. Less than a sale a year results in a larger number, or a worse ranking. A book without a sales ranking has yet to make a sale.
Similarly, Brent Sampson yields this list:
2,000,000+ Perhaps a single inventory/consignment copy has been ordered
1,000,000+ Current trends indicate total sales will most likely be under 40
100,000+ Current trends indicate total sales will most likely be under 200
10,000+ Estimate between 1 - 10 copies being sold per week.
1,000+ Estimate between 10 - 100 copies being sold per week.
100+ Estimate between 100 - 200 copies being sold per week.
10+ Estimate between 200 - 1000 copies being sold per week.
Under 10 Estimate over 1,000 copies per week
But again, being listed does not guarantee sales, and potential sales don't pay your bills.
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Apr 9, 2009
Amazon Sales Rankings
Dave Fortier provided some links to explain the Mystery That Is Amazon Sales Ranking.