Choosing a 7-Day vs 28-Day Attribution Window for Considered-Purchase DTC
A decision guide for DTC categories with 1-4 week consideration cycles: how switching from a 7-day to a 28-day attribution window reshapes channel RPV, and which window actually matches your time-to-purchase distribution.
Quick answer
Pick the window that covers roughly 80% of your time-to-purchase distribution. For 1-2 week consideration cycles (premium apparel, mid-tier skincare) a 7 or 14-day window is honest. For 2-4 week cycles (furniture, skincare regimens, higher AOV electronics) a 7-day window systematically under-credits Google and over-rewards last-touch Meta — use 28-day.
7-Day vs 28-Day Attribution Window (Considered-Purchase DTC)
The choice between crediting conversions to touchpoints within 7 days or 28 days of purchase — which reshapes channel RPV when consideration cycles exceed a week.
An attribution window is the look-back period during which a click or view can be credited with a conversion. For considered-purchase DTC categories — furniture, skincare regimens, premium apparel, higher-AOV electronics — the window length isn't a cosmetic setting. It rewrites which channels look profitable.
A 7-day window rewards fast-close channels (branded search, retargeting, email). A 28-day window pulls upper-funnel prospecting (Meta broad, YouTube, non-brand Google) back into the credited path. The correct choice depends on your actual time-to-purchase distribution — not on the platform default.
Most DTC stores inherit whatever window Meta and Google Ads defaulted to at setup — typically 7-day-click on Meta and 30-day-click on Google. That mismatch alone is enough to make cross-platform RPV comparisons meaningless. Before you touch budget, the two ad platforms have to be reading the same clock.
Why the window choice reshapes channel RPV
Every attribution window is a bet about how long a marketing touch stays causally relevant. On a 7-day window, a Meta prospecting impression seen on day 10 before purchase gets zero credit. On a 28-day window, that same impression is credited — and Meta's reported RPV jumps, sometimes 30-60% for skincare and furniture.
The effect isn't symmetric across channels. Branded search barely moves — those clicks convert within 48 hours. Non-brand Google and Meta broad prospecting shift the most. This is why a switch from 7 to 28 days can flip your channel-mix ranking without a single change in ad spend.
The view-through trap
On Meta, a 28-day window with 1-day-view enabled can inflate view-through RPV by 40-80% for skincare — much of it noise from users who would have converted anyway. If you widen the click window to 28 days, keep view-through at 1-day or turn it off entirely. See the sibling page on how 28-day windows inflate view-through RPV on Meta for skincare for the mechanics.
How to detect which window your data actually wants
Pull 90 days of orders and, for each order, compute the days between the first identifiable session (GA4 or your CDP) and the purchase. Plot the cumulative distribution. The 80th percentile of that curve is your honest window.
If P80 lands at 5-6 days, a 7-day window is fine. At 8-12 days you're in 14-day territory — the middle-path window that beats both for 1-2 week consideration cycles. At 15+ days, 28-day is the only choice that isn't lying to you. The sibling page on mapping your time-to-purchase distribution walks through the SQL.
How to fix a mismatched window
If your P80 says 28-day but you've been reporting on 7-day, switching is a real change to your KPIs. Non-brand Google RPV will rise 15-40% on furniture; Meta prospecting RPV will rise 25-70% on skincare regimens. Branded search barely moves.
Do the switch cleanly: recompute 90 days of historical RPV on the new window before you flip reporting, so the trend line has a continuous baseline. The sibling guide on switching from 7-day to 28-day without breaking your historical RPV trend covers the rebase procedure step by step.
For premium apparel: watch the sale-week distortion
Premium apparel compresses time-to-purchase during sale weeks (P80 drops from 10 days to 3-4) and stretches it during full-price weeks. A single fixed window will misread one of the two. Segment your RPV reporting by sale vs full-price weeks — the sibling page on reading 7-day RPV during sale vs full-price weeks explains the reporting split.
Experiments to run before you commit
Run parallel reporting for 30 days: same conversions, both windows side by side. Record channel RPV, CAC, and reallocation signals from each view. If the two views agree on the top three channels by RPV, window choice doesn't matter for your current spend mix. If they disagree, the 28-day view is almost always the more honest read for considered-purchase categories.
The follow-on decision — which window to use specifically when reallocating spend between Meta and Google — deserves its own analysis, because the two platforms disagree systematically on where consideration credit belongs. Recency bias among media buyers tends to defend the 7-day view even when the data doesn't; expect friction and bring the P80 chart to the meeting.
Frequently asked questions
There's no single standard. Meta defaults to 7-day-click, Google Ads to 30-day-click. For considered-purchase DTC (furniture, skincare regimens, premium apparel), 28-day is more defensible; for impulse categories under €50 AOV, 7-day is fine.
No. It changes which channels get credited for the revenue you already earned. Total orders and revenue are unchanged; the channel-level RPV, CAC, and ROAS numbers are what shift.
For considered-purchase DTC, Meta prospecting RPV typically rises 25-70% and non-brand Google 15-40%. Branded search and email move less than 5%. The exact numbers depend on your time-to-purchase distribution.
Be careful. A 28-day-click plus 1-day-view is usually defensible. A 28-day-click plus 28-day-view can inflate Meta RPV by 40-80% on skincare with mostly-illusory credit. Keep view-through short or off.
Common for premium apparel with sale spikes: a first-purchase peak at 2-3 days during promos and a second peak at 10-14 days at full price. Report both windows in parallel, or segment reporting by promo vs full-price weeks.
GA4 lets you configure a look-back window per conversion event (default is 30 days for acquisition, 90 days for other events). You can align it with Meta and Google Ads settings to keep cross-platform comparisons honest.
Yes, for 1-2 week consideration cycles. A 14-day window captures most of the consideration tail without the view-through noise a 28-day window invites. It's the honest choice for mid-tier skincare and premium apparel with P80 in the 8-12 day range.
A longer window increases the time to statistical significance because you have to wait for the tail of conversions to close before locking a result. For a 28-day window, budget at least 4-5 weeks of test runtime — not the 2 weeks a 7-day window would allow.
Yes, if you're comparing channel RPV directly. If Meta is reporting on 7-day and Google on 30-day, you're not comparing like with like — Meta will look artificially weaker on considered-purchase categories.
Quarterly, or whenever your product mix or price point shifts materially. A brand adding a €400 SKU to a €60 catalog will see the time-to-purchase distribution stretch — the old window may no longer fit.
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