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
The Original Search Marketing Event is Back!
SES Denver (Oct 16) offers an intense day of learning all the critical aspects of search engine optimization (SEO) and paid search advertising (PPC). The mission of SES remains the same as it did from the start - to help you master being found on search engines. Register today!