You may encounter some cases where the amount of Sponsored Sales exceeds the amount of All Sales, because of which the TACOS will be shown higher than the ACOS.
Premises about the attribution logic used by Amazon
Sales attribution is measured on a 7-day click-through attribution window. Meaning, if a user clicks on an ad, comes back up to 7 days later, and buys one of your products from your brand, Amazon will attribute the sale to that ad.
Sales are attributed to the last ad the user clicked on.
Why is there a discrepancy between "All Sales" and "Sponsored Sales" for a given strategy
Two possible explanations:
1) Sales attribution on different ASINs.
Based on our second premise, Sponsored Sales can be attributed to a Sponsored Product that has been clicked but not bought.
Example: A user clicked on the ASIN A1 which belongs to the S1 strategy, but eventually bought another product that is not included the S1 strategy.
2) Different sales aggregation times.
“Sponsored Sales” are reported at click time and “All Sales” are reported at sale time. There can be up to a seven-day time lag between these two events.
Example: A product can be promoted on Monday, the ad has been clicked and the user bought it on Wednesday. This transaction will be reported as a Sponsored Sale occurring on Monday and as an All Sale occurring on Wednesday.
Amazon updates its attributions metrics every day. These stats may evolve in time and can show different results if they are checked during the last seven days.