Meta Ads Attribution Window: 1-Day, 7-Day or 28-Day — What It Really Changes

An attribution window is the period during which Meta attributes a conversion to your ad after a user interacted with it. There are two types of interaction:

- **Click**: the user clicked on your ad - **View**: the user saw your ad but didn't click (impression > 1 second)

The attribution window combines these two dimensions: "X days after click" and/or "Y days after view."

**Available windows on Meta:** - 1-day click - 7-day click - 1-day click + 1-day view - 7-day click + 1-day view - 28-day click (available but no longer recommended by Meta) - 28-day click + 28-day view (available but very broad)

**Meta's default window** is 7-day click + 1-day view. This is what's used in your reports if you don't change the settings. It tends to inflate reported ROAS compared to economic reality.

**1-day click only:** The most restrictive window. It only attributes a conversion to Meta if the user clicked your ad AND converted within 24 hours. Recommended for: impulse purchases, flash offers, cross-channel comparisons (Google vs Meta).

Advantage: minimizes double-counting with Google Ads and other channels. Disadvantage: underestimates Meta for long purchase cycles (premium fashion, furniture, B2B).

**7-day click:** The intermediate window. Attributes conversions occurring up to 7 days after a click to Meta. Recommended for: most standard ecommerce products (FMCG, accessible fashion, beauty, electronics).

It's the right compromise for the majority of accounts — it captures typical purchase cycles without inflating double-counting too much.

**7-day click + 1-day view:** Meta's default window. Adds post-view conversions within 24 hours. Recommended for: evaluating Meta's top-of-funnel impact (awareness, branding). Not recommended for comparing with Google Ads (view-through artificially inflates Meta ROAS).

**28-day click:** For products with very long purchase cycles. Recommended for: B2B, high-ticket products (>€1,000), annual subscriptions. Warning: displayed ROAS can be 2-3x the actual economic ROAS.

The attribution window is configured in two places in Meta Ads Manager:

**1. At the ad set level (during creation or modification)** In the "Attribution" section of your ad set, you can choose the conversion window used for campaign optimization. This is the window Meta's algorithm uses to decide when to attribute a conversion to your ad during optimization.

**2. In your dashboard columns** In Ads Manager, click "Customize columns" or "Attribution window" at the top of your table. You can display multiple windows simultaneously for comparison (e.g., show 1-day click AND 7-day click in the same columns).

**Our recommendation:** configure your campaigns with 7-day click for optimization, and analyze your dashboards with 1-day click for cross-channel comparisons.

**Impact on optimization:** if you change the attribution window at the ad set level, Meta restarts a partial learning phase. Don't change this configuration on a running campaign unless absolutely necessary.

Double-counting is the #1 problem in cross-channel attribution. Here's what concretely happens:

A user: 1. Sees your Meta Reels ad (without clicking) → Meta starts its 1-day view window 2. Does a Google search and clicks on your Google Ad → Google starts its click window 3. Purchases on your site

**Result:** Meta counts this conversion (1-day view), Google counts this conversion (click). Your analytics tool (GA4, Shopify) records only one order. The Meta + Google total exceeds actual revenue.

**The real figure:** 40-60% of Meta view-through conversions (1-day view) are also counted by other channels. This figure is consistent with what we observe on accounts running both Google Ads and Meta simultaneously.

**The solution: a single source of truth** Use GA4 or your Shopify back office as the single source of truth for actual order count. Compare this figure with the sum of conversions reported by Meta + Google. The gap = double-counting. Distribute this gap across your channels proportionally to their budgets.

The ROAS difference based on attribution window can be substantial. Here's a real example (fashion ecommerce account, €15,000/month budget):

| Window | Reported Meta ROAS | |--------|-------------------| | 28-day click + 28-day view | 7.2x | | 7-day click + 1-day view | 4.8x | | 7-day click only | 3.9x | | 1-day click only | 2.7x |

ROAS goes from 2.7x to 7.2x depending on the window — without actual performance changing. Same account, same period, same campaigns.

**Consequence for budget decisions:** if you're managing your Meta budget based on a 7-day click + 1-day view ROAS of 4.8x while your actual economic ROAS (based on Shopify orders) is 2.9x, you're overbidding without knowing it.

**Our rule:** manage your bids and budget decisions based on the 1-day click ROAS compared to your source of truth (GA4 / Shopify). Analyze 7-day click to understand trends, but never make budget decisions based on 28-day windows.