5 min read

Ad Attribution: The Definitive Guide

Holly Shuffett
Holly Shuffett
Updated on
June 10, 2024
Ad Tech

What ad attribution is and best practices for measuring it. 

Ad attribution dominates retail media attention as demonstrating return on investment (ROI) is critical to attracting and retaining advertisers. In fact, a QueryClick survey found that 98% of respondents cite attribution as an important part of their tech stack. Clear ad attribution, equipped with first-party data and customer journey insights, is one of the best ways retailers can demonstrate ROI. 

RMNs must effectively report attribution if they want to surpass other advertising channels moving forward. 

What Is Ad Attribution? 

Ad attribution is the process of determining which user actions led to a desired outcome, like a sale or conversion, from an initial user ad click to the final conversion. ClearCode defines attribution as “...the process of identifying which touchpoints a consumer interacted with or was exposed to during a period of time before they completed a goal set by an advertiser or marketer.” 

Simply put, attribution is the mechanism of figuring out what customer actions led to a conversion. When a retailer reports that a user’s click on an ad led to a purchase, advertisers and marketers can better determine which ads and tactics contribute to sales or other goals. This way, they can improve and iterate on their campaigns since they understand which touchpoints are most effective and identify which parts of their marketing strategy drive results. 

When talking about ad attribution, these are some other important terms to know:

  • Customer journey. According to ClearCode, a customer journey is the path from initial brand awareness to the completion of a goal (e.g. a purchase or download). While all customer journeys differ, it's crucial to understand how its different stages can influence a user’s decision to complete a goal. 
  • Touchpoint. A touchpoint is any interaction a user has with a brand during their customer journey. This includes both active engagements, like clicks, and passive ones, like simply viewing an ad. Touchpoints are anything that might influence someone’s perception of a brand (website visits, reviews, videos, e-mails, etc.) 

When researching attribution, you may encounter the term “incrementality.” However, attribution focuses on short-term measurement, while incrementality covers mid-term measurement. For more information on incrementality, see our guide here (see section “Incrementality vs. Attribution.”) 

Why Attribution Matters 

Attribution gives advertisers the necessary insights to optimize campaigns and maximize ROI by accurately crediting specific touchpoints. This data-driven approach eliminates guesswork and identifies the most effective content or strategies to drive results and improve performance. 

Mastering ad attribution is essential for tracking performance, proving effectiveness, and securing ad spend by outperforming other channels. 

Benefits of Ad Attribution

The benefits of ad attribution include: 

  • Easier planning. The more you can learn from past campaigns, the better you can plan for future strategies. Attribution can help identify which keywords, ads, and campaigns generate the most leads and revenue, taking the guesswork out of campaign planning.
  • Improved reporting. Attribution creates detailed, data-backed reports showcasing ROI and justifying your budgets and strategies. 
  • Customer journey insights. On average, it takes eight touchpoints to close a sale. Attribution provides a detailed understanding of these touchpoints and how each one contributes to conversions. 
  • Cost-effective. Attribution helps identify underperforming campaigns so you can reallocate resources, focusing your budget on the most impactful touchpoints. 
  • Reach customers sooner. Attribution allows you to reach customers earlier in their purchase cycle, finding opportunities to influence them sooner on their path to conversion. 
  • Optimize bidding. Use insights on ad performance to improve bidding strategies for maximum impact. 
  • Focus on revenue. Ad attribution is focused on revenue generation. While vanity metrics like clicks, traffic, and time on site are important, attribution focuses on the ultimate goal: driving sales. 

Overall, ad attribution is indispensable for understanding the customer journey and making informed decisions to drive success. 

Attribution In Advertising: 9 Types Of Attribution Modeling 

Your goals, business, and customer interactions will determine which kind of attribution model is the best fit. Let’s explore each model and its pros and cons. 

1. Last-Click Attribution 

Also known as: Last-touch, last interaction, and last touchpoint attribution. 

Last-click attribution models are a kind of single source attribution model. 

Last-click attribution is the oldest and simplest attribution model, which is why it’s still a common default model, today. In a last-click attribution model, 100% of the credit for a conversion is assigned to the last known interaction or click before the conversion. 

Critics of this model include Andrew Covato, Founder & Managing Director of Growth by Science. “There’s still a ton of advertisers out there obsessed with last click. They think it’s so simple…that it’s just really tidy,” Covato said. “But the reality of it is that marketing measurement is not tidy, and if you try and make it tidy, you’re probably doing it wrong.” 


  • Easy to implement and understand
  • Allows you to analyze final touchpoints in the customer buying cycle


  • Oversimplified, ignores other influential marketing touchpoints in the customer journey 
  • Does not reflect real-world decision-making over multiple channels

Best for:  

  • Businesses with shorter sales cycles
  • Marketers focusing on converting anonymous visitors into leads or sales

2. First-Click Attribution

Also known as: First-touch, first interaction, and first touchpoint attribution. 

First-click attribution models are a kind of single source attribution model. 

As the name might suggest, first-click attribution is the opposite of last-click attribution -- a first-click model assigns all credit for a conversion to the first interaction or click. 


  • Easy to implement and understand
  • Useful for tracking how customers first discover products or services


  • Oversimplified, ignoring all subsequent touchpoints in the customer journey that help influence a conversion or sale

Best for:  

  • Advertising limited to two channels or fewer
  • Measuring brand awareness to uncover which channels drive new customer acquisition

3. Linear Attribution 

Linear attribution models are a kind of multi-touch attribution model. 

Linear attribution models evenly distribute credit across all touchpoints in the customer journey, offering a comprehensive overview of the entire path to conversion. While a linear attribution model may give a fuller picture of customer interactions than first or last-click models, it’s also rarely the case that every touchpoint is created equal. 


  • Ideal for measuring the overall performance of advertising campaigns
  • Provides a full picture of customer interactions


  • Treats all touchpoints equally, which rarely reflects true impact

Best for:  

  • Long-term marketing measurement, especially for businesses that drive conversions through multiple channels

4. Lead-Conversion Touch Attribution 

Lead-conversion touch attribution models are a kind of multi-touch attribution model. 

A lead-conversion touch attribution model is relatively complex, assigning conversion credit to touchpoints based on perceived impact on the conversion process. This model highlights the moments consumers are inspired to take action, but neglects pivotal touchpoints that may indirectly contribute to a conversion. 


  • Pinpoints the precise moments of lead generation 


  • May not assign credit weights correctly
  • May require additional resources and expenses to set up and maintain, unlike other simpler models

Best for:  

  • Determining and honing in on channels that perform well for specific brand goals

5. Time Decay Attribution

Time decay attribution models are a kind of multi-touch attribution model. 

An offshoot of the linear attribution model, the time decay attribution model gives the most credit to the touchpoint that is closest in time to the conversion, with remaining touchpoints given credit based on how far they are from the conversion. The further a touchpoint is from a conversion time-wise, the more its credit “decays.” 


  • Shows which campaigns are most effective at generating conversions
  • Weighs each purchase funnel touchpoint differently, more aptly reflecting real-life


  • Like linear models, time decay can credit too much (or too little) value to one specific touchpoint
  • Overemphasizes later touchpoints, potentially undervaluing earlier interactions 

Best for:  

  • Businesses with longer sales cycles, such as B2B marketing efforts 

6. Position-Based Attribution 

Also known as: U-shaped attribution.

Position-based attribution models are a kind of multi-touch attribution model. 

A position-based attribution model is more complex than other models, giving 40% credit to the first and last interactions in the customer journey, with the remaining 20% divided among the remaining touchpoints. This model tracks every single touchpoint, giving an overview of the customer journey, but assigns the most importance to the first and last touchpoints. Graphically, this creates a “U” shape, creating its other namesake, “U-shaped attribution.”


  • Provides a fuller picture of the whole customer journey 
  • Shows which touchpoints are effective at driving new customers and which channels are most dependable at converting visitors into leads or sales.


  • Not time-efficient 
  • Treats all touchpoints in the middle as equal and may give too much credit to less impactful touchpoints 

Best for:  

  • Businesses that rely on repeat purchases or conversions

7. W-Shaped Attribution 

W-shaped attribution models are a kind of multi-touch attribution model. 

Similar to U-shaped models, W-shaped attribution assigns varying degrees of credit to multiple touchpoints. In a W-shaped attribution model, 30% credit is attributed to the first touchpoint, lead conversion, and opportunity creation, with the remaining 10% divided among other touchpoints. Its name comes from the “W” shape it takes when charted on a graph.


  • Provides a fuller picture of the whole customer journey 
  • Considers brand awareness, consideration, and conversion 


  • May give too much credit to opportunity creation or brand awareness campaigns
  • Less effective for shorter sales cycles 

Best for:  

  • Businesses with longer sales cycles and multiple decision-makers 

8. Z-Shaped Attribution

Z-shaped attribution models are a kind of multi-touch attribution model. 

Like W- and U-shaped models, Z-shaped attribution models are named from the shape they make when you take a graphical-level view of how each channel receives credit. Z-shaped attribution models give equal attribution (22.5%) to all four crucial stages of a customer journey: first touch, lead conversion, opportunity creation, and customer close. The remaining 10% is distributed equally among any other touchpoints there may be. 


  • Provides a fuller picture of the whole customer journey 
  • Considers every interaction a customer has with your brand prior to conversion


  • Credit is apportioned formulaically, potentially giving too much or too little credit to various touchpoints 
  • Not effective for smaller businesses with a simple customer journey 

Best for:  

  • Larger businesses with a long and complex sales cycle where customers must effectively be nurtured and guided down the funnel 

9. Custom Attribution 

Custom attribution models allow advertisers to create their own rules for attributing credit to touchpoints based on specific campaign, customer, and journey characteristics. Although it’s one of the most complex attribution models, custom attribution is also the most tailored, giving marketers the ability to assign their own weights to each touchpoint. 


  • Highly accurate and tailored to specific business needs
  • Can consider the business’ industry, channels used, and buyer behaviors 


  • Complex to set up and requires expertise
  • Lacks transparency for advertisers, as they cannot compare a custom model to other attribution types easily 

Best for:  

  • Businesses with the resources and knowledge to develop a sophisticated attribution model

Choosing An Attribution Model

We explored nine attribution models, and depending on the platform, there are even more available. While variety allows you to tailor your strategy to meet specific brand goals, choosing an attribution model can feel challenging. 

Consider these factors when deciding which model to use: 

  • Length of sales cycle. Determine the type and duration of your sales cycle. Shorter sales cycles can benefit from simpler models like last- or first-click attribution. Longer sales cycles may require more nuanced, multi-touch attribution models like time decay or position-based attribution. 
  • Customer journey map. How are your customer touchpoints typically distributed across the marketing funnel? Are they spread out or condensed? Understand your touchpoint distribution across the marketing funnel to select a model that aligns with your journey. 
  • Campaign objectives. Define your campaign goals (e.g. brand awareness, lead generation, conversions). Objectives influence which model makes the most sense for your business. First-click might be ideal for brand awareness campaigns, for instance.
  • Business type. B2B businesses with longer sales cycles and multiple touchpoints may prefer multi-touch models like linear or position-based. B2C businesses may benefit from simpler models, especially if their customer journeys are shorter and less complex. 
  • Number of marketing channels. How many marketing channels do you use? Businesses leveraging multiple channels may want to use multi-touch attribution models to capture the full scope of their marketing efforts. 
  • Sales team. Consider how your sales team interacts with customers. Multi-touch models can better account for these interactions.

Choosing the right attribution model requires understanding your sales cycle, customer journey, and goals. By considering these factors, you can identify the attribution model that provides the most accurate insights for your business. 

How To Integrate Ad Attribution

How exactly do you integrate ad attribution? Amazon recommends these best practices: 

  • Take an omnichannel approach. Evaluate both online and offline marketing channels to understand the full customer experience and the true impact of different marketing efforts.
  • Investigate diverse leads. You should analyze both new and existing leads in your marketing funnel to fully understand their role in conversions. Existing leads can be just as critical for conversion as new leads.
  • CRM considerations. Use customer relationship management (CRM) data to rank and optimize information about prospective customer activities. Understanding how your audience moves down the funnel can give more insight into audience behaviors and should be a key part of your attribution strategy. 
  • Employ Automation. Implementing automated marketing tools can help ensure accuracy and efficiency when linking marketing channels to conversions. 

Build Vs. Buy 

When integrating ad attribution into your marketing strategy, consider these questions to determine the best solution for your business:

  • Is the attribution model based on accurate marketing data?
  • Is the attribution model customizable? 
  • Does the attribution tool rely on cookies?

Now, let’s explore three ways to integrate ad attribution. 

1. Blackbox Partners 

One option for ad attribution is to use tool-based analytics or a combination of attribution solutions. While convenient, this approach has its drawbacks. 

Relying on multiple tools to cover all data sources requires constant monitoring and adjustment to keep data sources in sync, leading to inconsistencies and data fragmentation. When the goal of attribution is to provide a complete and accurate picture of your customer journey, relying on decentralized data isn’t your best option. 

It’s also important to choose a partner that does not rely on cookies for tracking user interactions. Not only are cookies being phased out, but they also fail to capture the comprehensive view of users across multiple devices and touchpoints. One study shows that cookie-based analytics tools are only 20% accurate, meaning you could base important marketing decisions on 80% broken data. 

Above all else, blackbox partners often lack transparency regarding the use of your first-party data. Proprietary algorithms and methodologies can obscure how your data is processed and attributed, putting the reliability of these insights at risk. 

2. Building From Scratch

Building an attribution model from scratch offers tailored and accurate insights but is highly resource-intensive. 

A reliable in-house attribution solution must track, model, and analyze data across all customer touchpoints and channels. This requires months (minimum) of work, large development and analytics resources, and ongoing investment to adapt to changing market conditions. 

Building an attribution model involves these key steps: 

  1. Data collection. Aggregate data across all touchpoints using tracking tags or UTM parameters. These help track which channels, campaigns, or test variants drove users to your platform and how they interacted with it. Check out this Hightouch blog for more details on which UTM parameters to leverage
  2. Event data collection. Aggregate engagement data on your website or app, including conversion events like pageviews, add-to-cart actions, singups, product views, time on page, and purchases. 
  3. Combine and centralize your data. Prep your data for attribution modeling by ingesting all of the data from Steps 1 and Step 2 into a data warehouse. 
  4. Choose an attribution window. Decide on an attribution window. This is the defined period of time between a user interaction and a conversion, during which you assign credit to the interaction. For instance, a B2C e-Commerce business might set a 30-day window, where a conversion within 30 days of clicking on a paid ad gives credit to that ad. Note: Your attribution window should vary depending on your industry, product, and sales cycle. 
  5. Choose your attribution model. [See above section “Choosing An Attribution Model.”]

While building an attribution model from scratch offers tailored insights and flexibility, it is labor- and resource-intensive, with high costs and complex ongoing maintenance. For many business, these demands are too much to take on. 

3. Ad Attribution With Kevel 

Kevel blends the convenience of off-the-shelf solutions with the personalization of in-house builds. Kevel’s robust attribution logic accounts for several key factors, including: user, engagement, match type, and attribution window, all while maintaining a zero-touch approach to your data.  

Benefits of working with Kevel: 

  • Easy integration. Kevel seamlessly integrates with your existing data sources, providing immediate visibility into your marketing performance without manual intervention or complex setups. 
  • Customizability. Kevel allows for adjustments to attribution windows and match types to suit all business needs. 
  • Comprehensive attribution reporting. Kevel Audience uses comprehensive customer journey data to generate cross-channel, cross-device attribution reports. This omnichannel approach captures all touchpoints for a reliable and precise view of the whole customer journey. 
  • Real-time profile building. Kevel Audience assigns unique identifiers to each user upon arrival, building a real-time profile based on their browsing behavior. This ensures that even users who engage anonymously, have their actions integrated into their profile upon login, meaning better tracking and improved analysis -- aka no lost attribution opportunities. 
  • Offline data integration. Kevel integrates offline data like loyalty programs, CRM data, and in-store transactions, enhancing targeting and personalization strategies. 

If you’re looking for a sophisticated and user-friendly solution for ad attribution, consider Kevel to combine the ease of integration with extensive customization options. 

For more info on retail media, visit our quick guide here or download our eBook on Launching Your Own Retail Media Network. Interested in learning how Kevel can help you launch retail media advertisers will love? Get in touch today.

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