The short definitions
First touch credits the source that introduced the customer to you.
Last touch credits the source of the interaction immediately before they enquired.
Everything in between gets nothing in either model.
The same journey, two answers
A customer sees your van in March, searches your trade in June, clicks an ad, reads reviews, asks a neighbour, searches your business name, and calls.
First touch would credit the van, if it were trackable — usually it is not, so it credits the earliest recorded digital touch, often the ad.
Last touch credits the branded search, which is arguably the least persuasive step in the whole sequence. The customer had already decided; they were looking up the number.
Neither answer describes what happened, and both will be presented as though it does.
The predictable distortions
Last touch over-credits branded search and direct traffic. These are the final step for nearly everyone, including customers who came from a referral or a van.
Last touch under-credits awareness activity. Anything that introduced you but was not the final click looks worthless.
First touch over-credits discovery and ignores what actually closed. Under first touch, a remarketing campaign that recovered a lost customer gets no credit at all.
Why last touch is the default
Because it is simplest to implement and requires the least data. Most analytics reports use it by default, which means most small business marketing decisions are made on a last-touch view without anyone choosing it deliberately.
That is worth knowing before cutting a channel because it "produces no conversions".
What to do instead
For a small business, the practical answer is not a better model but a second source of truth:
Ask every enquiry how they heard about you and record it. It captures the van, the neighbour and the sign — none of which any model can see.
Where the asked answer and the tracked source disagree, that gap is informative rather than a problem. It usually shows how much of your work comes from sources the tracking cannot observe.
The channels most often wronged
Referral and offline presence, systematically, in every model. If a large share of your work comes from word of mouth, your analytics will attribute most of it to branded search — and you may conclude that search is carrying the business when reputation is.
Applying it
Check which model your reports use, then compare against what customers tell you. The difference is the most useful thing on the page.
Frequently asked questions
What is the difference?
First touch credits the source that introduced the customer; last touch credits the interaction immediately before they enquired. Everything in between gets nothing in either model.
Which model do most reports use?
Last touch, usually by default rather than by choice, because it needs the least data. Worth knowing before cutting a channel that appears to produce no conversions.
What does last touch over-credit?
Branded search and direct traffic, because they are the final step for nearly everyone — including customers who actually came from a referral, a van or a sign.
How do I correct for it?
Ask every enquiry how they heard about you and record it alongside the tracked source. Where they disagree, the gap shows how much work comes from sources tracking cannot see.