An Attribution Model is the rule set that determines how credit for conversions is assigned to marketing touchpoints in a customer's journey. When someone interacts with multiple ads before converting - seeing your Facebook ad, clicking a Google search ad, then purchasing via email - the attribution model decides which channel gets credit. This fundamental choice shapes how you measure ROAS, allocate budget, and evaluate channel performance.

Why Attribution Models Matter

Your attribution model directly determines which campaigns appear successful and which get cut. Using last-click attribution (the most common default) gives 100% credit to the final touchpoint - making retargeting and branded search look incredibly profitable while systematically undervaluing top-of-funnel awareness campaigns. If you're optimizing for CPA based on last-click data, you're likely starving the channels that introduce customers to your brand in the first place. The model you choose shapes your entire marketing strategy, often invisibly.

How Attribution Models Work

• Customer Journey: User sees Facebook ad (Day 1) → clicks Google ad (Day 3) → opens email (Day 7) → purchases

• Last-Click Model: Email gets 100% credit (most platforms default to this)

• First-Click Model: Facebook gets 100% credit

• Linear Model: Each touchpoint gets 33.3% credit

• Platform Impact: Facebook reports one ROAS, Google reports another, email platform reports a third - all using different attribution models

Real-World Example

A skincare brand runs ads on Facebook, Google, and sends email campaigns:

Using Last-Click Attribution (default):

• Email: $50,000 spend, 500 conversions → $100 CPA → Winner

• Facebook: $50,000 spend, 100 conversions → $500 CPA → Cut budget

• Google Search: $50,000 spend, 200 conversions → $250 CPA → Maintain

Using Data-Driven Attribution (actual impact):

• Email: 500 conversions, but 80% came from users who first saw Facebook ads

• Facebook: Gets credit for 320 conversions → $156 CPA → Actually profitable

• Google: Gets credit for 180 conversions → $278 CPA

The brand nearly killed Facebook - their main customer acquisition channel - because they were measuring success with the wrong attribution model. Switching to data-driven attribution revealed Facebook was driving most email conversions.

Common Attribution Mistakes

Learn More

• ROAS (Return on Ad Spend) - How attribution impacts ROAS calculation

• Cost Per Acquisition (CPA) - Why attribution changes your CPA metrics

Quick Takeaway

Attribution models determine which touchpoints get credit for conversions - most platforms default to last-click attribution that undervalues awareness campaigns, so audit your settings to measure true channel impact.