What is time-decay attribution?

Introduction
In the digital marketing landscape, understanding how conversions happen is vital for making smart decisions. Attribution models help advertisers assign credit to different ad interactions a customer has before completing a conversion, like making a purchase or signing up. One such model is the Time-Decay Attribution model in Google Ads.

Time-decay attribution gives more credit to the interactions that happened closer to the conversion and less credit to earlier interactions. This model is especially useful for businesses where the final decision-making steps are more influential than the initial touchpoints. It recognizes that the more recent an interaction, the more likely it influenced the user’s final action.

Time-decay is a smart alternative for advertisers who believe that not all clicks are equally important, and that the timing of engagement matters. It works well for campaigns with short sales cycles, remarketing strategies, and last-minute decision-making processes.

Understanding Time-Decay Attribution
Unlike linear attribution, which assigns equal credit to all touchpoints, time-decay attribution uses a weighted model. It gives progressively higher credit to more recent ad interactions and lower credit to earlier ones.

Google Ads applies a 7-day half-life in time-decay attribution. This means that an interaction that occurred 7 days before a conversion gets half as much credit as an interaction that happened 1 day before. If an interaction happened 14 days earlier, it would get just one-quarter of the credit compared to the most recent click.

This model assumes that the closer the click to the conversion, the stronger its influence on the final decision.

Example: Myntra Time-Decay Journey
Let’s say a customer is shopping for casual wear on Myntra and follows this path:

1. Clicks a YouTube video ad for “Myntra Casual Summer Looks” – 15 days before the purchase

2. Searches “Myntra dresses for women” and clicks a Search ad – 10 days before

3. Clicks a Display remarketing ad – 3 days before

4. Clicks on a Shopping ad and makes a purchase – same day

In time-decay attribution, Google would assign more credit to the Shopping and Display ads because they occurred closer to the conversion. The YouTube ad, being the oldest, would get the least credit. The distribution might look something like this (simplified):

• YouTube ad: 10%

• Search ad: 20%

• Display ad: 30%

• Shopping ad: 40%

This model reflects that while the earlier ads introduced and built interest, the more recent ads pushed the user toward final action.

Benefits of Time-Decay Attribution

1. Prioritizes Recent Engagements
Time-decay is ideal for businesses that believe the last few steps are the most crucial in closing sales. It helps you recognize and support those final pushes that lead to conversions.

2. Supports Remarketing Campaigns
Remarketing ads, which are often shown to users who’ve already visited your site, tend to be closer to the decision-making moment. Time-decay helps give them proper credit for their role in sealing the deal.

3. Great for Short Sales Cycles
If your products or services involve fast decisions — like fashion, travel deals, or local services — this model helps focus on the most time-sensitive interactions.

4. Useful for Flash Sales and Limited Offers
When running time-sensitive promotions or flash sales, time-decay attribution ensures your most recent ads (which highlight the offer) are given more importance than early exposure.

5. Helps Optimize Real-Time Campaigns
Because the model emphasizes current interactions, it guides marketers to improve what’s working now instead of overvaluing outdated clicks.

Limitations of Time-Decay Attribution

1. Undervalues Brand Awareness Campaigns
Early touchpoints like YouTube, Display, or influencer campaigns, which introduce your brand to the user, may get very little credit. This can lead to underinvestment in essential awareness-building strategies.

2. May Misrepresent the Full Journey
If your product requires a long consideration phase (such as electronics or high-end fashion), time-decay might overly reward bottom-funnel actions and ignore the research phase.

3. Doesn’t Account for Quality of Engagement
This model doesn’t differentiate between a brief accidental click and a highly engaged session—it only looks at timing. A recent, low-quality click could get more credit than a strong earlier one.

4. Less Ideal for Long Sales Cycles
In industries like real estate, B2B software, or luxury goods, where users research for weeks or months, this model may misrepresent the importance of early ads.

Example: Skechers Time-Decay Strategy
Let’s say a user is looking to buy Skechers walking shoes. Here’s how their journey might unfold:

1. Sees a Display ad 12 days before the purchase

2. Watches a YouTube product review ad 8 days before

3. Clicks a Search ad 4 days before

4. Finally clicks a Shopping ad and buys on the same day

Under time-decay attribution, the Shopping ad (being the final touchpoint) would receive the most credit. The Search ad would get significant credit as well. The YouTube and Display ads would get some credit, but less because they occurred earlier.

This shows Skechers how the last few interactions were more decisive in converting the user. It also helps them focus budgets on high-intent platforms while still recognizing the awareness-driven efforts.

When to Use Time-Decay Attribution

• When your business has short buying cycles

• If you’re running flash sales, holiday offers, or urgency-driven promotions

• When you heavily rely on remarketing or last-click channels like Shopping and Display

• If your goal is to optimize for immediate performance

• When you want to focus on high-intent moments closer to the point of sale

How to Set Up Time-Decay Attribution in Google Ads

1. Sign in to your Google Ads account

2. Go to Tools & Settings > Measurement > Conversions

3. Choose a conversion action (like Purchases, Leads, or Sign-ups)

4. Click Edit Settings

5. Under Attribution Model, select Time-Decay

6. Click Save

Once enabled, your conversion data and Smart Bidding (if active) will begin using this model to evaluate performance and optimize bidding.

Comparison with Other Attribution Models

• Last-click attribution gives 100% credit to the final click

• First-click attribution gives full credit to the first touchpoint

• Linear attribution divides credit equally across all interactions

• Position-based attribution gives 40% to the first and last clicks and 20% to middle ones

• Data-driven attribution uses AI to assign credit based on actual conversion behavior

Time-decay is a middle-ground model between linear and last-click. It values the path to conversion but puts emphasis on what happens closer to the finish line.

Conclusion

Time-decay attribution is a smart model in Google Ads that gives more credit to ad interactions closer to the time of conversion. It’s perfect for businesses where recent ads—like remarketing, Shopping, and branded Search—play a critical role in driving sales. Brands like Myntra and Skechers can benefit from this model when running fast-moving campaigns that rely on timely engagement. While it may not fully capture the value of early awareness-building efforts, it’s a powerful tool for short-cycle conversions, performance marketing, and optimizing real-time campaigns. If your business prioritizes timing and final decision points, time-decay attribution offers a flexible and actionable way to measure success.