Attribution modeling is how you answer the question "which marketing touchpoint deserves credit for this conversion?" Someone clicks a Google ad, leaves, comes back via an email, then converts on your landing page. Who gets credit? The ad? The email? The landing page? Your attribution model decides.
The most common models — last-click and first-click — are both wrong in predictable ways. Last-click overvalues bottom-of-funnel content like branded search. First-click overvalues awareness channels. Neither model tells you whether your landing page is actually doing its job. They just tell you where traffic came from.
What this means for landing pages
Here's the uncomfortable truth: if you're using last-click attribution (most GA4 default setups), you're probably overestimating the performance of your best landing pages and underestimating the importance of pages earlier in the funnel. A page that educates and builds trust but doesn't directly convert gets zero credit — even though it made the conversion possible.
For landing page optimization, focus less on which model is "correct" and more on whether your page performs its specific job in the funnel. A top-of-funnel page should be measured on engagement and micro-conversions, not final purchases. Match your metrics to the page's role.