What Is an Attribution Window?
An attribution window, sometimes called a conversion window, is the maximum time span between an ad interaction and a conversion event during which the platform will assign credit for that conversion to the ad. Advertising platforms such as Google Ads, Meta Ads Manager, and LinkedIn Campaign Manager each have their own default windows and allow advertisers to customise them. The most common settings are a 7-day click window, a 30-day click window, and a 1-day or 7-day view-through window for display and video campaigns.
Two types of interaction trigger an attribution window. A click-through attribution window starts counting from the moment a user clicks an ad. A view-through attribution window starts counting from when a user sees the ad without clicking. View-through windows are especially relevant for display and social media campaigns where users may see an ad, continue browsing, and convert later via a direct visit or organic search without ever clicking the original ad.
Understanding attribution windows is essential because changing or mismatching them distorts your return on ad spend data. If you run the same campaign for two months but compare the first month at a 30-day window against the second month at a 7-day window, the data is not comparable. Consistent settings are the foundation of honest reporting. Many South African advertisers unknowingly compare data across different windows when switching between platforms, leading to inaccurate conclusions about which channels are working.
Attribution Window In Practice
Consider a Cape Town property developer advertising new sectional title units in Milnerton. The typical buyer journey involves researching online over several weeks, attending a show house, returning to the website multiple times, and eventually submitting a contact form. If the developer uses a 7-day click attribution window, conversions from buyers who researched for three or four weeks before converting will not be attributed to the ad that initially drove the interest. A 30-day or even 60-day window would capture those buyers and give a more accurate picture of campaign performance.
On the other end of the spectrum, a Durban fast food franchise running Google Search ads for lunchtime promotions will see most conversions happen within minutes or hours of a click. A 7-day window is more than sufficient, and a 30-day window may inflate conversion numbers by capturing unrelated repeat visits. Matching your attribution window to your product's natural purchase cycle is one of the most impactful configuration decisions in Google Ads management, and it costs nothing to get right.
What an attribution window is
An attribution window (or conversion window) is the period of time after a person interacts with an ad or marketing touchpoint (such as clicking or viewing an ad) during which a subsequent conversion is credited to that interaction. Because people often do not convert immediately, they may click an ad today and buy days later, an attribution window defines how long after the interaction a conversion still counts as resulting from it. For example, a 30-day click attribution window means that if someone clicks an ad and then converts any time within 30 days, that conversion is attributed to the ad; a conversion after the window would not be. Attribution windows are set in advertising and analytics platforms, and they typically distinguish click-through windows (conversions after clicking an ad) from view-through windows (conversions after merely seeing an ad without clicking), often with different lengths. The attribution window matters because it directly affects how many conversions are credited to your advertising, and therefore your reported performance metrics (like conversions and ROAS): a longer window captures more of the delayed conversions that genuinely followed an interaction (crediting more conversions to the ads), while a shorter window credits only quick conversions (fewer). Understanding attribution windows matters because they shape how advertising performance is measured and reported, so knowing what window is being used, and choosing an appropriate one, is important for accurately understanding and comparing your campaigns' results, since the same campaign can look better or worse depending on the attribution window applied.
Choosing and interpreting attribution windows
Choosing an appropriate attribution window and interpreting results in light of it matters because the window directly affects reported conversions and metrics like ROAS, and mismatched or misunderstood windows lead to misleading comparisons. The right window depends on the business's typical sales cycle, how long people usually take to convert after first interacting: for quick, impulse purchases, a shorter window captures the relevant conversions, whereas for considered purchases or longer sales cycles (where people research and decide over days or weeks), a longer window is needed to credit the delayed conversions that genuinely resulted from the ad, since too short a window would under-count them and make the advertising look less effective than it is. So aligning the attribution window with your actual conversion timeframe gives a truer picture of performance. The window's effect on reported ROAS is direct: a longer window attributes more conversions (and revenue) to the ads, raising reported ROAS, while a shorter window attributes fewer, lowering it, so the same campaign's ROAS depends partly on the window used, which is why you must know and keep the window consistent when comparing campaigns or periods, and be cautious comparing figures measured with different windows. View-through windows (crediting conversions after mere ad views) should be considered carefully, since they attribute conversions to exposure without a click, which can inflate credit if not interpreted judiciously. For a South African business, the practical guidance is to set an attribution window that reflects its typical time from ad interaction to conversion (longer for considered purchases, shorter for quick ones), so reported conversions and ROAS reflect reality, and to be consistent and aware of the window when interpreting and comparing performance, since the attribution window materially shapes the numbers. Understanding this prevents both under-crediting advertising that drives delayed conversions and being misled by comparisons across different windows, so that advertising performance is judged accurately.
FAQ
What attribution window should I use for Google Ads in South Africa?
For most South African Google Ads campaigns, a 30-day click attribution window is a reasonable starting point. Shorter windows of seven days suit fast-purchase categories like e-commerce. Longer windows up to 90 days are better for considered purchases such as property, insurance, and professional services where buyers research extensively before converting.
How does the attribution window affect my reported ROAS?
A longer attribution window will typically show a higher ROAS because it captures more conversions that occurred days or weeks after the ad interaction. Shortening the window reduces counted conversions and lowers reported ROAS. Comparing campaigns using different window lengths produces misleading results, so consistency across all campaigns is essential.
What attribution window should you use for Google Ads in South Africa?
One that reflects your typical time from ad interaction to conversion. For quick, impulse purchases a shorter window suffices, while for considered purchases or longer sales cycles a longer window is needed to credit the delayed conversions that genuinely followed the ad, since too short a window under-counts them. There is no single correct figure, align the window with how long your customers actually take to convert, and keep it consistent for fair comparisons.
How does the attribution window affect your reported ROAS?
Directly. A longer attribution window credits more conversions (and revenue) to your ads, raising reported ROAS, while a shorter window credits fewer, lowering it, so the same campaign's ROAS depends partly on the window used. This is why you must know which window is applied, keep it consistent when comparing campaigns or periods, and be cautious comparing figures measured with different windows, since the window materially shapes the reported numbers.