Attribution is how you assign credit for a conversion to the posts, ads, emails and visits a customer touched along the way.
Why it matters
Social often starts a customer's journey without closing it. A last-click view can make social look useless when it is actually doing the introducing.
Common models
Last click gives all credit to the final touch; first click to the first; linear splits it evenly. For most small businesses, the practical answer is consistent UTM tagging plus asking new customers "how did you hear about us?".
