Before buying, one question stands above the rest: how many units will I sell? The BSR is your best clue.
What the BSR is
The Best Sellers Rank ranks a product within its category based on its recent sales. BSR #100 sells far more than BSR #100,000. It is relative to the category: a BSR of 5,000 in Beauty is not the same as in DIY & Tools.
From BSR to a sales estimate
The BSR is converted into estimated monthly sales using curves specific to each category. A low, stable BSR = reliable demand; an erratic BSR = occasional sales.
The pitfalls
- A single BSR data point is not enough: look at the 30-90 day average.
- Watch out for swings: a BSR spike after a promotion is not the norm.
- Compare like with like: only within the same category.
Good practice
Cross-check the sales estimate against the number of sellers: 300 sales/month shared among 15 FBA sellers means only 20 units for you. Analyzer+ shows both the estimate AND the competitive split, so you don't fall for the best-seller illusion.