What Is an Attribution Window and How Should You Set It?

Your attribution window is the number of days after an initial click or visit during which a conversion is still credited to a campaign. It's one of the most consequential settings in podcast attribution — and one of the most frequently set incorrectly.

Set it too short, and you'll miss conversions from listeners who needed time to decide. Set it too long, and you'll over-attribute conversions that were driven by other channels.

Here's what you need to know.

The Basic Concept

When a listener clicks your podcast tracking link, a session begins. The attribution window determines how long that session remains "active" for attribution purposes.

Example with a 14-day window:

• Day 0: Listener clicks tracking link
• Day 7: Listener returns to your site and adds to cart
• Day 12: Listener buys
• Result: Conversion is attributed to the podcast campaign ✓

Same scenario with a 7-day window:

• Day 0: Listener clicks tracking link
• Day 7: Listener returns to your site and adds to cart
• Day 12: Listener buys
• Result: Conversion is NOT attributed to the podcast campaign ✗

The listener's entire purchase journey was influenced by the podcast ad — but the 7-day window declared the session expired before the purchase happened.

Why Podcast Attribution Windows Should Be Longer

Podcast advertising has a longer consideration cycle than most digital channels. Here's why:

Audio-first discovery. Podcast listeners hear about your product while doing something else — driving, running, cooking. They can't immediately click and buy. The intent is planted, but the action is delayed.

High-consideration products. Podcast advertisers tend to sell products that require research before purchase: subscription software, health supplements, financial services, home products. These aren't impulse buys.

Trust-based channels. Host-read podcast ads work because of the host's relationship with their audience. But that trust takes time to convert — listeners often listen to the same show for weeks or months before acting on a recommendation.

Research on podcast listener behaviour shows:

• Median time from first ad exposure to purchase: 7–14 days
• 30% of podcast-driven conversions happen after day 14
• 15% of podcast-driven conversions happen after day 21

A 7-day attribution window misses roughly one-third of all podcast-driven purchases.

Recommended Windows by Product Type

| Product Type | Recommended Window | Reasoning | |---|---|---| | E-commerce (impulse) | 14 days | Shorter consideration, but still needs buffer for delayed action | | E-commerce (considered) | 30 days | Products requiring research, comparison shopping | | SaaS (free trial) | 30 days | Trial sign-ups may come quickly, but trial conversions lag | | SaaS (enterprise) | 60–90 days | Long sales cycles with multiple decision-makers | | High-ticket (finance, health) | 60 days | Significant consideration period, high trust required | | Subscription (food, CPG) | 30 days | Repeat purchase patterns, moderate consideration |

When in doubt, start with 30 days. You can always tighten the window later once you have data on your actual conversion delay distribution.

How to Check Your Actual Conversion Delay

The best way to set your attribution window is to look at your own data. In Castlytics, the campaign detail view shows an average conversion delay — the mean number of days between first tracking event and conversion.

If your average conversion delay is 8 days, a 14-day window provides a comfortable buffer. If it's 18 days, you need 30 days minimum.

Look at the full distribution, not just the average. If 90% of your conversions happen within 14 days but 10% happen at days 15–30, a 14-day window would be systematically undercounting a meaningful portion of conversions.

Window Length vs. Attribution Accuracy

There's a real tension between window length and attribution accuracy.

Longer windows capture more conversions — but they also increase the risk of attributing a conversion that was genuinely driven by a different channel. If a listener clicks your podcast link, then sees your Google ad 25 days later, and buys on day 27, should that be attributed to the podcast or to Google?

This is where last-touch attribution is helpful. Under last-touch, the Google ad gets credit for the day-27 conversion (because it was the last touch before purchase), not the podcast click. The podcast link opened the consideration — but the Google ad closed it.

With a 30-day podcast attribution window AND a last-touch model:

• Day 0: Podcast link click → session starts
• Day 25: Google ad click → session now has a newer last touch
• Day 27: Purchase → attributed to Google ad

This is the right attribution. The podcast session is superseded by the Google session.

Without last-touch (pure first-touch with a long window), the podcast would get credit for a conversion that Google actually drove.

Practical rule: Use last-touch attribution with a 30-day window. This gives you a generous window to capture delayed podcast conversions while correctly attributing the credit when a different channel influences the final decision.

What About Promo Codes?

Promo code attribution doesn't have a "window" in the same sense. A promo code sale is attributed to the campaign that owns that code regardless of when it happens — whether that's day 2 or day 200 after the ad aired.

This is actually one of the biggest advantages of promo code attribution: it captures long-tail conversions that any window-based system would miss.

A listener who heard your ad in January and only gets around to buying in April will still be attributed correctly through the promo code, even if their tracking link click has long since expired.

The Window Setting Nobody Talks About: When to Reset

Should a second click from the same visitor reset the attribution window?

Most attribution systems reset the window on any new campaign touchpoint. If a listener clicks your link on day 1, then clicks it again on day 20, the window resets from day 20. This means their purchase on day 35 (which would have been outside the original 30-day window) is now captured.

This is generally the right behaviour. A second click represents renewed intent — the listener is still actively engaged with the campaign. It's reasonable to extend attribution accordingly.

Common Window Mistakes

Using a 24-hour window. Almost always wrong for podcast advertising. This setting catches only immediate purchasers — a tiny fraction of podcast-driven buyers.

Using the same window across all campaigns. A direct-response campaign for a $29 impulse product might appropriately use 14 days, while a high-ticket software campaign needs 60. Customise per campaign.

Never reviewing your window setting. Once you have 6+ months of conversion data, look at your actual conversion delay distribution and adjust. The right window is an empirical question, not a guess.

Assuming a longer window always means better results. A 90-day window on a $19 product is probably capturing conversions that were driven by other channels. Longer is only better up to the point where it's capturing your actual customer decision timeline.

Setting the Window in Practice

In Castlytics, the attribution window is set per campaign at the time of creation and can be adjusted retroactively. The recommendation:

1. Start with 30 days for all campaigns
2. After 60 days of data, review the average conversion delay in your campaign reports
3. For campaigns where 95%+ of conversions happen within 14 days, tighten to 14 days
4. For campaigns where significant conversions are happening at days 25–30, extend to 60 days
5. Revisit every quarter as your campaign mix evolves

The goal isn't to have the longest possible window — it's to have the most accurate window. A window calibrated to your actual customer behaviour is the one that gives you the most trustworthy ROAS numbers.