Aaron Gerdes

In the article quoted before on anti-marketing design, Scoble has tangent:

It’s amazing how few corporate types get that the quality and engineering thought behind your HTML matters more than whether your site is pretty or not.

Another way to put it: if your building is beautiful but not up to code, you’re going to have problems.

Three reasons XHTML/CSS (business translation: recent) standards-compliant code is good for your business:

1. Ease maintenance/updating/redesign costs. Good code will separate the design/layout code from the formatted content. Doing so means that if you’d like to change part of a page layout, you edit one CSS file instead of ten or hundreds of HTML files.
2. Lower costs for deploying content in other forms. Related to the above. Create multiple stylesheets for a single body of content is easy. Now your website works on mobile phones and prints cleanly (yes, people still do that). Some will disagree, but I think standards-compliant code deploys better across multiple browsers and platforms. And it degrades gracefully (meaning old browsers will still see a readable version).
3. Accessibility: Better search engine ranking, wider audience. Standards-compliant code is more organized and clean, therefore easily parsed for computers and people. This means screen readers and other assistive devices can process the information on your site for the sight-impaired, for example. It also (I’ve heard this but cannot verify, so take with salt) can improve your search engine ranking by removing clutter and increasing your keywords-to-file-weight ratio.

Find out more about web standards.