Amazon has launched a shopping-signal enhanced last-touch attribution model that will become the standard for conversion metrics like purchases, sales, and ROAS. Advertisers will still be able to access metrics that include all ad views within a 14-day window as all views metrics through Unified Reporting interfaces and APIs, with changes affecting Sponsored Brands, Sponsored Display vCPM campaigns, and Amazon DSP campaigns serving ads in the Store.
Read more on this update: https://advertising.amazon.com/en-us/resources/whats-new/view-attribution-updates-for-amazon-store-ads/?ref_=a20m_us_wn_gw