Attribution in Google Ads is the process of determining how credit for conversions (sales, leads, sign-ups) is assigned across different ads, keywords, and campaigns. It answers the question: Which ad interaction influenced the customer the most?
In a customer journey, people rarely convert after a single click. They might click on multiple ads, search for your brand several times, or interact across different channels before making a purchase. Attribution helps advertisers understand which touchpoints deserve credit, so budgets and strategies can be adjusted accordingly.
Types of Attribution Models in Google Ads
Google Ads provides several attribution models, each with a different way of assigning credit:
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Last Click
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Gives 100% of the credit to the last ad the user clicked before converting.
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Simple but may undervalue earlier interactions.
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First Click
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Assigns all credit to the first interaction.
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Highlights discovery campaigns but ignores nurturing and closing ads.
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Linear
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Distributes credit evenly across all touchpoints.
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Useful for seeing the impact of multi-step journeys.
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Time Decay
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Gives more credit to clicks that happened closer to the conversion.
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Good for shorter sales cycles.
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Position-Based (U-Shaped)
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Assigns 40% credit to the first and last clicks, and distributes the remaining 20% across the middle interactions.
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Balances discovery and closing campaigns.
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Data-Driven Attribution (DDA)
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Uses Google’s machine learning to assign credit based on actual observed data.
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Recommended when you have enough conversion volume for reliable insights.
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Why Attribution Matters
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Smarter Budget Allocation: You can identify which campaigns assist conversions rather than just close them.
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Better Bidding Decisions: Smart bidding strategies use attribution data to optimize in real-time.
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Full-Funnel Visibility: Instead of only rewarding the last ad, you see the role of awareness and consideration campaigns.
Example of Attribution in Action
Imagine a customer journey:
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A user clicks a Display Ad introducing your brand.
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A week later, they click a Generic Search Ad while researching solutions.
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Finally, they click a Branded Search Ad and complete the purchase.
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Last Click Model: 100% credit goes to the branded search ad.
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First Click Model: 100% credit goes to the display ad.
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Linear Model: Each of the three touchpoints gets 33%.
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Position-Based Model: Display ad = 40%, Branded search = 40%, Generic search = 20%.
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Data-Driven Attribution: Google analyzes the role each click had based on past data and assigns credit accordingly, maybe 30% Display, 20% Generic Search, 50% Branded Search.
Which Attribution Model is Better?
The “best” model depends on your goals and data volume:
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Small advertisers or simple funnels: Position-Based or Linear provides a balanced view.
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Longer sales cycles: Time Decay gives more weight to touchpoints closer to the sale.
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Most businesses with enough data: Data-Driven Attribution (DDA) is generally the best choice. It adapts to your actual customer journey instead of relying on assumptions.
Key Takeaway
Choosing the right attribution model in Google Ads helps you understand the bigger picture of customer behavior. For most advertisers with enough data, Data-Driven Attribution is the most accurate. However, the best model depends on your goals, sales cycle, and how much conversion volume you have.
By analyzing attribution, you’ll make better decisions about where to invest your budget and how to maximize your return on ad spend.