All you have to do is cut and paste a URL into Magento's GWO tool and bam - you're ready to optimize that landing page.
Seriously, if you're not convinced you need to be testing - then stop everything and read these links:
Landing Page Optimization: Guessing vs. Testing
Coherency in Landing Page Testing
Landing Pages: Test Now or Forever Hold Your Peace
Testing Applies to Widgets and Accessories, Not Just Landing Pages
Testing Landing Pages Includes Testing Best Practices
Assembling Your Landing Page Optimization Dream Team, Part 2
Introducing SES Online
Want to view one of the sessions you missed or listen to an especially informative presenter a second time? SES New York sessions are available for purchase on ClickZ Academy's new e-Learning site. SES is now Online!