Subversive Ways To Use Analytics To Gain Upper Management's Support
Start by swallowing your pride and telling the CMO that her idea is great--but you'd like to run a test just to make sure it's optimal. Keep the old site functional while the new site goes live, and get traffic and conversion stats, as well as customer feedback from both.
And using competitive insight can also help to gain upper management's support. For example, if you can show them that that traffic to your top two competitor's Web sites is more than double your own, or that the competition owns a particular keyword across multiple engines, then the head honchos will probably allow you to SEO the site to your heart's desire.