Attribution
Last-click attribution
Also called last touch.
Last-click attribution is a model that gives all credit to the last campaign touch before the conversion. It is the default in many tools because it is easy to explain.
How it is measured
For each conversion, the model finds the latest tagged touch within the lookback and gives it the full value. Direct visits are usually ignored if an earlier campaign touch exists.
Check how the tool treats untagged visits. Some tools pass credit past direct to the last known source; others credit direct. That setting can swing totals significantly.
Worked example
A garage-door installer gets 96 quote requests in a month. Last-click gives paid search 58, since people often click an ad when ready to call. Email gets 9 and the local radio spot gets 0 because it has no link.
The installer asks new callers how they heard of the company. Of 40 answers, 14 name the radio spot. The last-click view undercounts a channel that cannot carry a click tag.
How it differs
Last-click attribution credits the closer. First-click attribution credits the opener. Last-click favors channels near the purchase, like search, and undercounts awareness work.
Common errors
Cutting upper-funnel spend because last-click shows no return. Ignoring offline touches. Letting direct take credit. Using different lookbacks in different tools. Treating it as the only truth.
In practice
Use it as the baseline view, then add one other model and a customer survey question. Judge channels that cannot carry a link by other evidence.