Clicks and impressions describe attention. They do not tell you whether marketing is helping the business. The more useful questions begin after someone lands on your site.
Decide which actions matter, such as an enquiry form, a call, a WhatsApp message, a booking or a purchase, and record each one as a conversion. Measure every channel against the same definitions.
Then follow the enquiry further. Which ones became qualified conversations? Which became customers? Even a simple shared sheet between marketing and sales can show which campaigns bring useful leads, not just more of them.
Review the numbers on a regular rhythm, alongside notes on what changed that week, such as new creative or a price change. Measurement is most valuable when it leads to a decision: keep, adjust or stop.