GA4 uses a data-driven attribution model by default for most properties with sufficient conversion volume. To check which model is active, navigate to Admin (bottom left gear icon), then under Property settings click Attribution settings. You'll see your current attribution model and lookback window there. If you don't have enough data for data-driven, GA4 falls back to last click. For actual analysis of how attribution works across your channels, the Model comparison report is more useful. Go to Advertising > Attribution > Model comparison in the left nav. This shows how different attribution models (data-driven, last click, first click, linear, position-based, time decay) would credit the same conversions. You can toggle between models and see which channels gain or lose credit under each approach. Most Canadian businesses we work with see meaningful differences. Paid search often gets overcredited under last-click because it captures bottom-funnel demand, while organic, email, and display lose credit for their earlier touchpoint contributions. Data-driven typically shifts 15–30% of conversion credit away from last-click channels when there's actual multi-touch behaviour in your funnel. A few things to watch: GA4's data-driven model needs at least 400 conversions per month and sufficient path diversity to activate. Below that threshold you're stuck with last-click, which is why newer sites or low-volume B2B funnels often can't use it. Also, the lookback window matters—default is 90 days for most conversions, but you can't customize it per conversion action like you could in Universal Analytics. At Ottawa SEO, we check attribution settings during every GA4 audit because misunderstanding your model leads to bad budget decisions. If you're running multi-channel campaigns (SEO + paid + email) and still on last-click, you're likely underfunding top-of-funnel work. The Model comparison report should be part of your monthly review, not something you check once and forget.