Even if your site is not an ecommerce site set up fake or 'pseudo-ecommerce' where you make up values, say $1, for key metrics like a sign-up. Conversion rates

Even if your site is not an ecommerce site set up fake or 'pseudo-ecommerce' where you make up values, say $1, for key metrics like a sign-up. Conversion rates give you 'value': - 500 visits from source A, 10 sign ups, 2% conversion rate - 100 visits from source B, 10 sign ups, 10% conversion rate