The most important metrics involve what users do once they land on your site. From a web development perspective, that is the key to making sales.
One thing that always bugs me is that when website owners and developers attempt to fix problems of a site, the solution they gravitate to is more search engine friendly than user friendly
Search engines don’t buy any products, or fill out lead forms, but people do. So designing a site that is search engine friendly should always come 2nd to designing a site that is user friendly. Every site’s goal should be to please the end users first.