Signal

A signal is any piece of data a platform uses to decide who to show your ads to and how to optimize.

Clicks, purchases, page views, time on page, and the identifiers tied to them all feed the model. The more clean, accurate signal you send back about what actually happened, the better the platform can find more people like your real buyers. Weak or missing signal leaves it guessing.

This matters more now that browser tracking has gotten leaky. After Google reversed its plan to kill third-party cookies and later wound down Privacy Sandbox, the ground kept shifting, so advertisers lean on first-party signal they collect and send directly, like server-side purchase events, instead of relying on the browser to remember everything.

Garbage signal trains the model to find garbage. If you send back events that misfire or mislabel actions, the platform optimizes hard toward the wrong people and you pay for it in wasted budget.

Feed it clean, or it learns your mistakes.