It amazes me how often I talk to companies that spend a relatively large sum on their website, but then allow it to just sit there. Sure, the new site may mean you are no longer embarrassed by your website and no longer find yourself making excuses for it. And there is a definite value to that.
But is it actually bringing more business your way? Very often the answer to this is 'no'. Even worse, it frequently leads to a reduction in traffic to your site. Now that's a nasty surprise for the CEO.
Why does they see a reduction in traffic? Well, sometimes SEO is an afterthought.