Attribution Windows Explained: 1-Day vs 7-Day vs 28-Day

An attribution window is the period after someone clicks or views your ad during which a resulting sale still gets credited to that ad. A 1-day window counts only what happens within 24 hours, a 7-day window counts sales up to a week later, and a 28-day window stretches that to four weeks. The ads, the budget and the customers stay identical — but the longer the window, the more sales the platform claims, and the better your return on ad spend looks.

That single setting is why two marketers can study one campaign and reach opposite conclusions. This guide shows you exactly how, using one campaign judged under three windows, and then covers what every window quietly hides.

What an attribution window actually is

Think of it as a credit deadline. Someone clicks your Instagram ad on Monday. They buy on Thursday. Did the ad cause that sale?

Under a 1-day click window, no — the deadline passed on Tuesday, so the platform reports zero. Under a 7-day click window, yes — one purchase, full revenue credit. The customer behaved identically in both cases. Only the measuring tape changed.

Windows come in two flavours, and mixing them up causes most of the confusion:

• Click-through windows count sales after someone deliberately clicked or tapped your ad.
• View-through windows count sales after someone merely saw the ad — no click required. Meta calls these view-through conversions; Google Ads uses the same term.

A setting written as 7-day click, 1-day view means: credit any purchase within 7 days of a click, or within 1 day of an impression. The view-through half is where reported numbers inflate fastest.

The three windows at a glance

Window	What it counts	Tends to flatter	Most useful for
1-day click	Purchases within 24 hours of a click	Impulse buys, retargeting, low-price products	Stress-testing an inflated ROAS; fast-moving goods
7-day click	Purchases up to a week after a click	Most direct-to-consumer e-commerce	Day-to-day optimisation; the common default
28-day click	Purchases up to four weeks after a click	Courses, insurance, B2B, high-ticket items	Payback and budget planning on long cycles

ROAS, by the way, means return on ad spend: revenue credited to the ads divided by what you paid for them. A ROAS of 2.0 means two rupees of tracked revenue per rupee spent.

One campaign, three verdicts

Here is an illustrative example — the numbers are invented to show the mechanics, not drawn from a real brand.

A mid-sized Indian skincare brand runs Meta ads for 30 days. Spend: ₹5,00,000. Average order value: ₹1,800. Gross margin: 55%, so each order contributes about ₹990 before ad costs. That puts break-even at roughly 1.8 ROAS.

Now the same 30 days, reported under four settings:

Attribution setting	Purchases credited	Revenue credited	ROAS	Cost per purchase
1-day click	320	₹5,76,000	1.15	₹1,563
7-day click	520	₹9,36,000	1.87	₹962
7-day click, 1-day view	610	₹10,98,000	2.20	₹820
28-day click	640	₹11,52,000	2.30	₹781

Translate those into profit and the stakes get sharper. On 1-day click, the campaign looks like it lost about ₹1,83,000 (320 orders × ₹990, minus ₹5,00,000). On 7-day click it looks marginally profitable, up around ₹15,000. On 28-day click it looks comfortably positive, up roughly ₹1,34,000.

Three verdicts: kill it, keep it, scale it. The brand’s bank statement never changed.

So which number was true?

None of them, strictly. An attribution window answers a narrow question — which sales happened close enough in time to an ad interaction — not the question you actually care about, which is how many sales happened because of the ads.

In our example, suppose the brand ran a geo holdout test: show ads in some states, withhold them in comparable ones, and compare. Say that test suggested about 450 incremental orders. That is below the 7-day click figure of 520 and well above the 1-day figure of 320 — meaning the default window over-credited, and the short window under-credited. At 450 orders the campaign was slightly under break-even.

This is the central lesson. A window is a reporting convention. Only an experiment — a holdout, a geo test, a conversion-lift study — tells you about cause.

What attribution windows hide

The report is not finished yet

Meta and Google Ads both credit conversions back to the day of the ad interaction, not the day money changed hands. A sale on day seven is stamped onto day one. So yesterday’s ROAS keeps climbing for a week after the fact.

Judge a campaign launched three days ago on a 7-day window and you are reading a half-filled report. Many premature campaign shutdowns are really just this.

View-through credit for people who scrolled past

In the table above, switching on 1-day view added 90 purchases. Those people never clicked. Some genuinely saw the ad, remembered the brand and searched for it later. Others were scrolling past a video for two seconds and were going to buy anyway. The report cannot tell you which.

Every platform claims the same sale

Windows run in parallel across platforms. A shopper clicks a Meta ad, then a Google search ad, then buys. With a 7-day window on Meta and a 30-day window on Google Ads, both count one full conversion. Add up platform-reported revenue and you will routinely exceed what your store recorded. The gap is not a bug — it is overlapping windows plus each platform’s own self-reported view.

Long windows blur cause and effect

A 28-day window means a creative change you made today will not be fully measurable for a month. You gain completeness and lose the ability to iterate quickly.

Windows change optimisation, not just reporting

This is the part most guides skip. On Meta, the attribution setting is not only a reporting choice — it is the signal the delivery system learns from.

Set a campaign to 1-day click and the algorithm optimises toward people who buy within 24 hours. Over time, that nudges delivery toward existing-intent audiences and impulse buyers, and away from people who need a few days to decide. A 7-day setting lets the system find slower converters.

So switching from 7-day to 1-day does not merely shrink the numbers on screen. It can genuinely change who sees your ads. Changing a reporting view in Ads Manager is harmless; changing the ad set setting is a strategy decision. Current options and defaults shift over time — verify yours in the Meta Business Help Center before you commit budget.

Default windows across platforms

Defaults differ, which is why cross-platform comparisons mislead so easily. At the time of writing:

• Meta: 7-day click is the usual default. The 28-day click option was removed as an ad set setting after Apple’s App Tracking Transparency rules arrived in 2021, though 28-day figures remain viewable in reporting comparisons.
• Google Ads: conversion windows are configurable, commonly defaulting to 30 days and extendable to 90. See Google Ads Help.
• Google Analytics 4: uses a longer lookback — 90 days for most conversion events by default. See Analytics Help.
• LinkedIn Ads: commonly 30-day click, reflecting slow B2B cycles. See LinkedIn Ads Help.

A 2.0 ROAS on LinkedIn and a 2.0 ROAS on Meta are not comparable numbers.

The India angle: longer decisions, COD and festive spikes

Short windows punish Indian marketers more than most, for three practical reasons.

Consideration cycles run long. A ₹40,000 upskilling course or a ₹25,000 insurance premium involves family discussion, WhatsApp follow-ups and a counsellor call. Compressing that into 7 days hides most of the journey; a 28-day view is far closer to reality.

Cash on delivery stretches the timeline. Where orders are placed, then confirmed by phone, then delivered and paid for, the revenue event your system records can sit well outside the click window.

Festive buying is deliberately delayed. During Diwali sale weeks, shoppers discover products in advance and wait for the discount to land. Your pre-sale awareness campaigns did the work; a short window hands all the credit to the retargeting ad that ran on sale day.

Common mistakes

1. Comparing windows across platforms. Meta at 7-day versus Google at 30-day is not a fair fight. Align windows before you compare, or compare each channel only to its own history.
2. Judging fresh campaigns on long windows. A 7-day window needs seven days of settling. Give it that time, or read a 1-day view for early signal.
3. Switching windows mid-flight and treating the trend as real. Your ROAS chart will step up or down on the day you changed the setting. That is the measurement moving, not the business.
4. Summing platform revenue. If Meta plus Google plus affiliates exceeds your actual revenue, trust your own order data and treat platform numbers as directional.
5. Reporting the flattering window upward. If your board sees 28-day click with view-through included and nobody says so, you have created a number no one can act on.
6. Expecting any window to prove incrementality. It cannot. Only a holdout can.

What this means for you

• Pick one window as your official number and write it down. For most e-commerce, 7-day click with no view-through is a defensible standard. Put the setting in your report header so every reader sees it.
• Match the window to your real buying cycle. If your average time from first touch to purchase is 18 days, a 7-day window will permanently understate your ads. Check this in your own CRM or order data, not in Ads Manager.
• Read two windows side by side. A big gap between 1-day and 7-day click means slow consideration — useful intelligence for your creative and remarketing plan. A tiny gap means impulse buying.
• Treat view-through conversions as a separate line item, never folded silently into your headline ROAS.
• Wait out the window before killing anything. Decide on day eight, not day two.
• Run one holdout per quarter. Pause a region or an audience for two weeks and compare. It is the only number that tells you whether the spend caused anything.
• Reconcile to your own books monthly. Platform totals are each channel’s best case. Your order management system is the truth.

Frequently asked questions

What is an attribution window?

An attribution window is the length of time after someone clicks or views an ad during which a resulting conversion is still credited to that ad. A 7-day click window credits any purchase made within seven days of the click. The window affects what the platform reports, not what customers actually do.

What does 7-day click attribution mean?

It means a sale counts toward an ad if the buyer clicked that ad at any point in the previous seven days. It is the common default on Meta ads. If the same setting also says 1-day view, purchases within 24 hours of simply seeing the ad are counted too, even without a click.

Does changing the attribution window change my actual sales?

No. Reporting windows change only what you can see. The one exception matters, though: on Meta, the ad set attribution setting also guides the delivery algorithm, so changing it there can shift who your ads reach and therefore affect real results over time.

Should I use a 1-day or 28-day attribution window?

Match it to how long your customers take to decide. Low-price impulse products are reasonably served by 1-day or 7-day click. Considered purchases such as courses, insurance, property or B2B software need 28 days or more, otherwise you will under-report badly and cut campaigns that are working.