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Keep the business scope, currency, date range and measurement definition consistent. Advertising-attributed sales and order-date account sales do not answer the same question.

A change in one metric is a starting point for investigation, not proof of a cause.
Keep the business scope, currency, date range and measurement definition consistent. Advertising-attributed sales and order-date account sales do not answer the same question.
Review stock availability, pricing, promotions, delivery conditions, listing changes and campaign activity alongside performance. A sales increase cannot automatically be credited to one intervention.
Record the observation, the possible explanations and the next action. Specify what will change, who approves it and which measurement window will be used before making further adjustments.
Marketplace, fulfillment, E-Commerce, or the systems between them.