Sub-hub · Attribution

Attribution is broken. Triangulation is the operating answer.

Last-click attribution died with iOS 14. Multi-touch attribution overstates digital and undervalues brand. The 2026 operating standard is triangulation: marketing mix modeling for strategic allocation, holdout/incrementality tests for tactical decisions, and platform-reported metrics as directional input — not source of truth.

§ 01 · Definition

What is attribution?

Marketing attribution is the discipline of assigning revenue credit to marketing touchpoints. Methods include single-touch (first-touch, last-touch), multi-touch (linear, time-decay, U-shaped, data-driven), marketing mix modeling (statistical regression on aggregate data), and experimental (incrementality holdouts, geo-lift tests). No single method is correct; mature programs triangulate multiple methods against different decisions.

§ 02 · Context

Why attribution matters in 2026

  • 01

    Last-click attribution overcredits bottom-funnel channels (branded search, retargeting) by 30–50% — driving budget away from awareness channels that actually fuel growth.

  • 02

    iOS 14 and cookie deprecation broke the digital-attribution stack that DTC brands operated on for a decade.

  • 03

    Marketing mix modeling (MMM) is the only attribution method robust to identity changes — and the only method investors trust for strategic allocation.

  • 04

    Incrementality testing (holdouts, geo-lift) is the only attribution method that can prove causation, not just correlation.

  • 05

    The brands hitting profitable growth in 2026 use 3+ attribution lenses, weighted by decision type — not a single source of truth.

§ 03 · Metrics

Core metrics & concepts

Every metric below has a definition page in the Fairview glossary — formulas, benchmarks, and worked examples.

First-Touch Attribution

First-touch attribution gives 100% of conversion credit to the first marketing touchpoint. It overvalues top-o

Last-Touch Attribution

Last-touch attribution gives 100% of conversion credit to the final marketing touchpoint. It overvalues bottom

Multi-Touch Attribution

Multi-touch attribution is a marketing measurement approach that distributes credit for a conversion across ev

Marketing Mix Modeling (MMM)

A statistical method that uses regression analysis to measure how each marketing channel (paid search, social,

Media Mix Modeling

Media mix modeling estimates the revenue contribution of each media channel — TV, digital, print, out-of-home,

Attribution Window

Attribution window = time period during which a conversion can be credited to a marketing touch. 1-day view /

Incrementality

Incrementality measures how many conversions were caused by marketing activity versus what would have happened

Conversion Lift

Conversion lift measures the incremental increase in conversions caused by your advertising. Median B2B SaaS c

Holdout Test

A holdout test withholds advertising from a random 10–20% of users to measure conversion without the ad. The h

Geo-Lift Test

A geo-lift test uses geographic markets as test and control groups — running campaigns in some markets, withho

True ROAS

Return on ad spend adjusted for product returns, order cancellations, discounts, and cost of goods sold. While

Blended ROAS

Total revenue divided by total advertising spend across all paid channels, without attributing revenue to any

MER (Marketing Efficiency Ratio)

Total revenue divided by total marketing spend across all channels. MER is a channel-agnostic measure of overa

ACoS (Advertising Cost of Sales)

ACoS = (Ad Spend / Attributed Sales) × 100. Amazon advertising's efficiency metric — inverse of ROAS. Best-in-

TACOS (Total Advertising Cost of Sale)

The percentage of total revenue spent on advertising across all paid channels. Calculated by dividing total ad

Ad Fatigue

Ad fatigue = audience overexposure causing engagement decline. CTR drops 30%+ from baseline, CPM rises, conver

§ 09 · By industry

For your business model

§ 11 · FAQ

Frequently asked

Why did last-click attribution stop working?

Three reasons. (1) iOS 14 limited deterministic conversion tracking. (2) Cookie deprecation broke cross-domain identity. (3) Consumer journeys span 10+ touchpoints across devices — single-touch models structurally can't capture them.

What replaced last-click for DTC brands?

A stack: MMM for monthly/quarterly allocation, incrementality holdouts for tactical campaign decisions, and platform-reported attribution as a directional check. No single tool — operators triangulate.

Do I need MMM at my stage?

Most DTC brands benefit from MMM starting around $5M annual ad spend. Below that, simpler methods (holdouts + MER tracking) are more cost-effective. Above $50M ad spend, MMM is table stakes.

What is the difference between MMM and MTA?

MMM (marketing mix modeling) uses statistical regression on aggregate data — robust to identity changes, slow to update. MTA (multi-touch attribution) uses user-level data — granular, broken by privacy changes. MMM for strategy; MTA for tactics (where it still works).

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Editorial standards

Sources & references

Fairview maintains a public bibliography for every topic hub. Each citation below was verified at publication. We update sources every 12 months as new benchmark studies are released. See our editorial standards.

  1. 1 Marketing Mix Modeling in the Privacy Era — Meta Open Source (Robyn), 2024. View source .
  2. 2 DTC State of the Industry 2025 — Common Thread Collective, 2025. View source .
  3. 3 Incrementality Testing for Performance Marketing — Northbeam Research, 2025. View source .

Fairview cites primary sources only — government data, academic research, industry benchmarks from named publishers, and official vendor documentation. See our editorial standards.