It must be the first question answered during a website design.
Re: web design, Tesla Motors gets it. Confederate Motor Company doesn’t. Sure, I’d love to park either of those companies’ machines in the garage, but I can’t make it past Confederate’s mission statements to their products.
Ask “What do we do?” before the first wireframe is sketched. If you can visually explain to a visitor why he should (or shouldn’t) be spending time with you, you win.
For Confederate, the answer to that question shouldn’t be: “Rebel.” The answer should be: “We build motorcycles.”
You only have a split second.