There are many facets to a great site, but without question the single most important aspect is automation.
If each visitor action requires a reaction by a human, that’s you, you can easily spend your day doing simple tasks that can easily be automated.
Automation includes, but limited to, email followup, answer visitor questions, process and ship orders, deliver audio and video content requested … and much more.
If your site does not have automated programming, it will fail!