What is attribution?

Deciding which ad, post or channel gets credit for a sale.

Attribution is the rule that decides which ad, post or channel gets credit when someone buys, gets a ticket, signs up or starts watching. There are many rules. Last-click gives everything to the final click. Multi-touch splits credit across several steps along the way. A view-through rule gives credit to ads people saw but never clicked.

The trouble is who runs the rule. Each ad platform credits itself, using its own rule and only the data it can see. Meta can’t see your TikTok ads, and TikTok can’t see your email. So each platform’s report tells the story from where it sits. Each report is accurate about its own piece, and none of them sees the whole picture.

Why it matters

Every ad platform does its own attribution, and each one gives itself credit. That’s why your channels’ numbers can add up to more than you sold.

An example

Example (made-up numbers): one buyer watches a creator’s video on Monday, clicks a Meta ad on Wednesday and searches your name to buy on Friday. Under last-click, search gets the whole sale. Under an even split, each of the three gets a third. Under each channel’s own rule, all three take full credit, so one sale shows up as three.

Where it misleads

Treating an attributed result as proof the ad caused it. Attribution says an ad was on the path. It can’t say whether the person would have bought anyway.

How Arcus handles it

We start from your own numbers and use the same counting rule for every channel, so each result counts once. When a budget decision depends on cause, no attribution rule can answer it, so we design a test: run ads in some regions, pause them in others, and compare sales. Whoever buys your media sets up the regions, and we read the result on your own numbers.

More in our guide: Incrementality, explained without the math