What does attribution do?
You help users answer the hardest question in marketing: which of my efforts actually caused this conversion and this revenue? Attribution is where marketers lose the most money — to channels that look good in one dashboard and terrible in another, to "direct" and "branded search" that hide the real source, and to models that quietly encode an opinion as if it were fact.
This skill has two pillars. Know which one the user needs before you dive in:
- (A) Interpretation — choosing an attribution model, picking a measurement approach, and reconciling the conflicting numbers your tools report. This applies to everyone, even with zero engineering.
- (B) Own your attribution (first-party) — instrumenting and stitching attribution yourself when you control the site/app. This is the build track. Use it when the user says "I want to track this myself" or is hitting a conversion that lives on a domain they don't own.
Most requests start with (A). Reach for (B) only when they control the surface and want to build.
Product context: check for .agents/product-marketing.md and read it if present — business type, sales cycle, and primary conversion drive almost every recommendation here.
Boundaries — what this skill does NOT own
State these up front so you don't rebuild neighboring skills:
- General event tracking, tracking plans, UTM setup, GA4/GTM → analytics. Attribution assumes tracking exists. The line: analytics = "what events and how to fire them"; attribution = "how touches join to conversions and survive to revenue."
- Ad-platform pixels, CAPI, server-side conversion tracking → ads (
references/conversion-tracking.md). Attribution consumes platform-reported numbers and corrects for their bias; it doesn't set up the pixels. - Pipeline stages, lead lifecycle, CRM revenue dashboards → revops. Attribution feeds pipeline data; it doesn't define stages.
- Showing up in / measuring AI search → ai-seo. Attribution names AI traffic as a blind spot only.
Pillar A — Interpretation
1. What attribution can and can't tell you
Set expectations before touching a number:
- Attribution is directional, not truth. It's a model of causality built from incomplete data (cookies expire, sessions fragment, offline touches vanish, people research on one device and buy on another). Treat it as a strong hint, never a verdict.
- Every model is an opinion. "First-touch" says the first ad gets all the credit; "last-touch" says the closing click does. Both are wrong in opposite directions. Choosing a model is choosing whose story to believe — say so out loud.
- The attribution gap is normal. The sum of channel-reported conversions almost always exceeds real conversions, because every platform claims credit for the same sale. Your job is to shrink and explain the gap, not to make the numbers tie out perfectly. They won't.
When a user demands one true number, reframe: "We can get you a defensible, consistent number and a read on which channels are trending up. A single objective truth doesn't exist — here's why, and here's what we use to make decisions anyway."
2. Attribution models
The six standard models and when each one lies:
| Model | Credit rule | Best for | How it lies |
|---|---|---|---|
| First-touch | 100% to the first known touch | Top-of-funnel / demand-gen valuation; short cycles | Ignores everything that closed the deal; over-credits awareness channels |
| Last-touch | 100% to the last touch before conversion | Direct-response, quick e-comm | Over-credits bottom-funnel + branded search/direct; ignores what created demand |
| Last non-direct | 100% to last touch, skipping "direct" | A cheap fix for direct pollution | Still single-touch; just moves the blind spot |
| Linear | Equal credit to every touch | Long, multi-touch journeys where every step matters | Treats a throwaway visit like a demo; flatters high-frequency channels |
| Time-decay | More credit to touches nearer conversion | Longer cycles where recency matters | Under-credits the top of funnel; still an assumption, not a measurement |
| Position-based (U-shaped) | 40% first, 40% last, 20% middle | B2B with clear "created" + "closed" moments | The 40/40/20 split is arbitrary; middle touches get shortchanged |
| Data-driven (algorithmic/Shapley) | Credit from modeled marginal contribution | High-volume accounts with enough conversions | A black box; needs volume; can't see offline/dark touches it was never fed |
Rules of thumb:
- Never report a single model in isolation for a long sales cycle. Show first-touch and last-touch side by side — the truth lives between them, and the gap between them is the insight.
- Data-driven attribution needs volume (Google Ads historically gated it behind ~3,000 ad interactions and ~300 conversions in 30 days; it has since relaxed the minimums and made DDA the default, but low volume still makes it noise dressed as science). Use position-based instead when you're thin.
- The model matters far less than being consistent and pairing it with an out-of-model sanity check (Pillar A §4, self-reported).
For the model math, worked examples of one journey scored six ways, and Shapley explained plainly, see references/attribution-models.md.
3. The three measurement paradigms
Models split credit within your tracked data. Paradigms are how you get at causality — increasingly rigorous, increasingly expensive:
| Paradigm | What it is | Answers | Needs | Watch out |
|---|---|---|---|---|
| MTA (multi-touch attribution) | Stitch user-level touches, apply a model | "Which touchpoints appear on converting journeys?" | Clean cross-device user-level tracking | Cookie loss + privacy have gutted user-level data; it silently under-measures |
| MMM (media/marketing mix modeling) | Top-down regression of spend vs. outcomes over time | "What's each channel's aggregate contribution, including offline/brand?" | 2–3 yrs of weekly data, spend variation | Correlational; slow to react; needs real budget swings to learn |
| Incrementality (geo holdout, PSA, ghost ads, on/off) | Controlled experiment: exposed vs. withheld | "Did this channel cause lift I wouldn't have gotten anyway?" | Ability to withhold; enough volume for significance | The gold standard, but you can only test a few things at a time |
How to choose: small budget / short cycle → good UTM + last-non-direct + a self-reported survey beats a fancy model. Mid budget, several channels → MTA for day-to-day + periodic incrementality tests on your biggest line items. Large budget, offline + brand spend → MMM for the portfolio + incrementality to validate MMM's coefficients. Incrementality is the tiebreaker whenever two channels both claim the same conversions.
Decision table by budget × sales cycle × channel count, and how to read a geo-holdou