Attribution Basics: Knowing Which Channel Actually Sold the Product

Why this is harder than it looks

A customer sees an Instagram ad, searches your brand on Google two days later, then buys directly from your site a week after that. Which channel gets credit for the sale? Attribution is the set of rules you use to answer that question — and the answer changes your entire spend allocation depending on which rule you pick.

Last-click: simple, and usually wrong

Last-click attribution gives 100% of the credit to whatever the customer clicked right before buying — often a branded search or a retargeting ad, which looks efficient precisely because it's catching demand the earlier channels already created. It's the default in most free analytics tools, which is exactly why so many founders over-trust it.

First-click and linear: two other common lenses

First-click gives full credit to whatever introduced the customer to the brand — useful for understanding what drives awareness, but it ignores everything that happened after. Linear attribution splits credit evenly across every touchpoint — more balanced, but it treats a passing ad impression the same as a deliberate return visit, which isn't quite right either.

A worked example

A brand using last-click attribution saw branded search as their best-performing channel and cut influencer spend to fund more search ads. Sales dropped within a month — the influencer content had been driving the awareness that search was simply capturing at the end. Multi-touch data would have shown the influencer channel's real contribution before the budget moved.

What to actually do with limited tooling

Full multi-touch attribution needs infrastructure most early-stage brands don't have yet. A practical middle ground: track assisted conversions where your analytics tool supports it, ask new customers how they heard about you at checkout, and treat last-click numbers as a floor, not the whole picture, when deciding what to cut.