Attribution Models

An attribution model defines which touchpoint in the customer journey a conversion – meaning a purchase, a sign-up, or another desired action – is credited to. In most cases, a shopper interacts with several ads before buying: they see a display ad, click a Sponsored Products ad, return through a Google search, and finally make the purchase. The attribution model determines who gets the “credit” for that purchase.

The choice of attribution model has a direct impact on how campaigns are evaluated: the same budget can deliver completely different performance figures depending on the model. Anyone who wants to assess their advertising channels fairly and allocate budgets sensibly needs to understand which model their platform uses – and where its limits lie.

With last click attribution (also called last touch), the final touchpoint before the purchase receives 100% of the credit. If a user first sees a display ad, then clicks a Sponsored Brands ad, and finally buys through a Sponsored Products ad, the Sponsored Products campaign alone is credited with the sale.

Advantage: Simple, clear, easy to follow. Well suited when the customer journey is short (e.g., impulse buys).
Disadvantage: Systematically overvalues lower-funnel channels and undervalues awareness and consideration touchpoints. In a last-click model, display and video campaigns often appear “ineffective” even though they were what sparked the purchase in the first place.

With first click attribution, the first touchpoint receives 100% of the credit. In the example above, the display ad would be credited with the entire sale because it established the first contact.

Advantage: Shows which channels bring new customers into the funnel. Valuable for brands that prioritize new-customer acquisition.
Disadvantage: Ignores everything that happens after the first contact. Retargeting and conversion campaigns are systematically undervalued.

For Sponsored Ads (Products, Brands, Display), Amazon uses a last click attribution model with a 14-day lookback window for clicks and a 14-day window for View-Through Conversions. A purchase is credited to the last clicked ad, provided the click occurred within the past 14 days.

One important note: because Amazon only considers the last interaction, double counting can occur when a user clicks ads from different sources. DSP, Sponsored Products, and Amazon Attribution each have their own attribution – so a single sale can theoretically show up in multiple reports at the same time. Tools like Amazon Marketing Cloud help resolve these overlaps.

In practice, neither of the two single-touch models is perfect. The most honest answer comes from multi-touch models or data-driven attribution – but these require more data, more tools, and more analytical expertise. For day-to-day Amazon Advertising, the most important thing is to know that Amazon uses last click, and to factor that knowledge into how you manage your campaigns.