Attribution modeling assigns conversion credit across the multiple touchpoints a prospect hits before they buy or submit a lead form. If someone finds you through organic search, comes back via a Facebook ad, then converts through a direct visit, attribution modeling determines how much credit each channel gets for that sale. The default in Google Analytics is last-click attribution, which gives 100% credit to the final touchpoint before conversion. That's misleading because it ignores everything that built awareness and trust earlier in the funnel. A prospect might discover you through SEO, research via email, then convert after clicking a retargeting ad. Last-click says the ad deserves all the credit. First-click does the opposite, crediting only the initial discovery channel. More sophisticated models split credit differently. Linear attribution divides credit equally across all touchpoints. Time-decay gives more weight to interactions closer to conversion. Position-based (U-shaped) credits 40% to first touch, 40% to last, and splits the remaining 20% among middle interactions. Data-driven attribution uses machine learning to assign credit based on actual patterns in your conversion data, but it requires significant volume to work properly. For most businesses under $500K annual ad spend, we recommend starting with position-based or time-decay models in Google Analytics 4. They acknowledge that both discovery and closing matter without requiring the data volume that algorithmic models need. Track this in GA4 under Advertising > Attribution, and compare models side-by-side to see how credit shifts. The practical issue is that attribution only works within platforms that can track the full journey. Cross-device behaviour, offline conversions, and privacy restrictions (iOS blocking, cookie deprecation) all create gaps. At Ottawa SEO, we layer attribution data with channel-specific metrics and month-over-month lead quality assessments. If SEO traffic converts at higher lifetime value even when it's not the last click, that context matters more than any model's credit allocation. Attribution guides budget decisions but doesn't replace understanding your actual customer journey.