Attribution
Attribution is the method used to share out the credit for a conversion among the ads and channels a person came across before converting.
Before buying, someone may see a video on connected TV, an ad on social media and a banner, and end up searching for the brand on Google. A last-click model gives all the credit to search; a first-touch model, to the video; linear and position-based models split it by fixed rules; data-driven models assign it according to the statistical weight of each touchpoint. In 2023 Google retired the rule-based models from Analytics 4 and Google Ads, leaving last click and data-driven as the options.
No model is neutral. Last click rewards the channels that capture demand (search, retargeting) and penalises those that create it (video, CTV, out-of-home), and almost all of them ignore what leaves no click, such as an ad seen on TV or a visit to a shop. That is why attribution is complemented by incrementality studies and marketing mix models, which measure the effect of each medium from aggregated sales.
