‘Website Optimizer is a free tool that helps AdWords advertisers test different landing pages and determine which one drives the most conversions. A true multivariate testing tool, Website Optmizer allows you to test variations of headlines, promotional copy, and images. The tool allows you to update your site with the winning test combination and continue to experiment’

The program is currently in beta, but hopefully it will get a wider release soon.

Andrew Goodman has a good write-up, and a few concerns:

“(1) I’ll probably use this stuff, if they let me; (2) I’m afraid of the larger consequences, especially if Google begins to “organize and make universally accessible — to itself — the world’s confidential marketing information“

Google could be a little more transparent about the last point.