During her keynote at the O’Reilly Velocity Conference, Google’s Marissa Miller (VP of Search and UX) tells us how seemingly insignificant tweaks to the code behind websites can make incredible differences.

This phenomenon is best illustrated by a single design tweak to the Google search results page in 2000 that Mayer calls “The Billion Dollar HTML Tag.” Google founders Sergey Brin and Larry Page asked Mayer to assess the impact of adding a column of text ads in the right-hand column of the results page. Could this design, which at the time required an HTML table, be implemented without the slower page load time often associated with tables?

Mayer consulted the W3C HTML specs and found a tag (the “align=right” table attribute) that would allow the right-hand table to load before the search results, adding a revenue stream that has been critical to Google’s financial success.

Rich Miller’s post on the keynote

Yahoo! got the ball rolling a few years ago when some of their engineers started presenting front-end strategy at conferences like SXSW. They advised sites to serve content from multiple domains, set expires headers correctly, include Javascript in ways that wouldn’t pause page loading, etc. Response was excellent and Yahoo! launched their Exceptional Performance team, releasing best practices on their site and making available the YUI CSS/JS framework and Firefox site performance analysis plugin YSlow.

Though Google’s contributed to the public knowledge of site optimization, they lagged badly until recently offering the AJAX library CDN and the excellent Page Speed Firefox plugin. Hey, YSlow never told me that specifying image dimensions in the HTML tag reduces page load time! Converted.

Now Google has also released twenty or so articles on improving your site’s speed by better organizing CSS, using compression, optimizing your PHP/JS, caching, etc.

If you’re in a position to test some of this, it’d be pretty interesting to hear what kind of results you see.