Why Are Predicted Monthly Sales and Historical Monthly Sales Inconsistent?

1. We have a powerful web crawler engine capable of processing massive amounts of data. It crawls basic product information from various Amazon sites daily, such as prices, review counts, and especially Best Sellers Rank (BSR).
2. Based on our accumulated historical sales data over the past three years and user feedback, we have a general understanding of the relationship between BSR and sales for each site and major category.
3. By correlating daily sales with daily BSR, we can preliminarily predict monthly sales based on the daily average BSR of the ASIN.
4. At the same time, we also consider the historical sales trend of ASIN to improve the accuracy of sales predictions.

The monthly sales of any single child ASIN actually correspond to the sales of the parent, i.e., the sum of the sales of all child variations.
 

When using the ASIN sales prediction tool to query different child ASINs, there may be slight deviations in the corresponding monthly sales. This is because Amazon's BSR updates every hour, and the SellerSpirit system retrieves data for each child ASIN at different times, resulting in some fluctuation in BSR rankings.
The ASIN sales prediction tool retains the predicted sales results based on the individual BSRs of each ASIN:
 

On the other hand, the historical monthly sales of ASINs under the competitor analysis function have been standardized to account for the sales of various variations. That is, each variation ASIN uses the same ASIN's sales as the total sales of the listing:
 

Therefore, inconsistencies between predicted monthly sales and historical monthly sales may occur.