Ecommerce analytics measures brand versus performance spend by tracking each budget's distinct impact, direct response metrics like ROAS and conversion rate for performance spend, and lagging indicators like branded search volume, direct traffic, and lower CAC over time for brand spend, rather than judging both against the same short-term ROI window. Brand spend and performance spend are not competing for the same job. Measuring them with the same yardstick is why so many founders think brand marketing does not work.