What Is Attribution? — Free Tool
Attribution is the rule that decides which touchpoint gets credit for a conversion. The common models, why last click flatters search and starves social, and how windows change the answer.
The rules that decide which touchpoint gets credit for a conversion. Attribution does not discover the truth, it applies a model you chose, and different models produce different winners.
What it is
Attribution is the set of rules that decides which touchpoint gets credit for a conversion. Someone sees a Reel, searches your name a week later, clicks an ad, then buys. Attribution decides who gets the sale, and there is no objectively correct answer, only a model you chose.
How it is measured
There is no formula, there are models. Last click gives everything to the final touch; first click gives everything to the discovery touch; linear splits credit evenly; time decay weights recent touches more; data-driven models let the platform estimate contribution statistically. Each is paired with a window, such as Meta's default 7-day click plus 1-day view, which defines how long a touch stays eligible for credit.
Commonly misunderstood
The biggest misconception is that attribution measures reality. It applies a rule, and changing the rule changes the winner without anything happening in the market. Last non-direct click, the long-standing web analytics default, systematically flatters search and direct while starving the awareness channels that created the demand in the first place, because those touches happen early. Meanwhile ad platforms use their own windows and include view-through credit, so each will claim the same conversion. That is why summing conversions across Meta, Google, TikTok and your analytics tool produces more sales than the business actually made.
When it matters
Attribution matters most when you are deciding what to cut. Before removing a channel because it shows few last-click conversions, check what happens to total revenue when you pause it. That test beats any model.
Related terms
Features
- The main models explained: last click, first click, linear, time decay, data-driven
- How attribution windows work, and why widening one lifts reported performance
- View-through credit and why it makes social look better than analytics does
- Why last non-direct click systematically undercredits awareness channels
- A linked ROI calculator for judging the programme rather than the last touch
Frequently asked questions
What is the default attribution model?
There is no universal default. Google Analytics 4 now uses a data-driven model with last non-direct click available, Meta Ads uses 7-day click and 1-day view by default, and most other ad platforms default to last click inside their own window.
Why does last click undervalue social?
Because social usually appears early, when someone first learns you exist, and search or direct usually appears last, when they already know your name. Last click hands all the credit to the final step and none to the one that created the demand.
What is an attribution window?
The period after a click or an impression during which a conversion still counts. Meta's default is 7-day click plus 1-day view. Widening the window increases reported conversions without changing anything about the campaign.
What is view-through attribution?
Credit given for a conversion after someone saw an ad without clicking it. It is the most generous form of credit and the main reason platform-reported numbers exceed what web analytics shows.
How do I pick a model?
Pick the one that matches the decision. Last click is fine for judging a bottom-of-funnel search campaign. For deciding whether social is worth funding at all, use a model that credits earlier touches, and sanity check the whole thing against total revenue.
