Marketing Attribution is the method of assigning credit to marketing touchpoints that contribute to a conversion or sale.
It matters because strategy keeps channels from competing with each other. When this concept is clearly defined, the team can connect budget, audience, creative, offer, tracking, and reporting to revenue instead of chasing disconnected metrics.
Example
A customer discovers a brand through search and later returns through email before purchasing. An attribution model assigns credit among those recorded interactions; the assignment depends on the model and available data, not only on the final visit.