Accessibility, SEO, and maintainability are the business reasons. But the larger reason, the why, is that its easier for a computer to parse. If you want to be

Accessibility, SEO, and maintainability are the business reasons. But the larger reason, the why, is that its easier for a computer to parse. If you want to be part of the Semantic Web[1], you should make your pages as machine-readable as possible. Makers of screen readers will thank you too. <table> means tabular data, not layout. But since no one follows that, parsers first have to determine which way you meant <table>. This is an unneeded complication. If everyone used the right tags (<div> and <span> for layout, everything else is semantic), writing a parser would be insanely easy and we could spend our time on more interesting problems. [1] http://en.wikipedia.org/wiki/Semantic_Web http://en.wikipedia.org/wiki/Semantic_Web