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
Meet Your Favorite Search Engine Watch Contributors
Many of SEW's leading expert contributors will be at ClickZ Live, the new online and digital marketing event kicking off in New York (March 31-April 3). Hear from the likes of: Thom Craver, Josh Braaten, Lisa Barone, Simon Heseltine, Josh McCoy, Lisa Raehsler, Greg Jarboe, Dan Cristo, Joseph Kerschbaum, John Gagnon, Eric Enge and more!