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
Optimising Digital Marketing Campaigns with Search, Social and Analytics
At SES London (9-11 Feb) you'll get an overview of the latest tools, tips, and tactics in Paid, Owned, Earned, Integrated Media and Business Intelligence to streamline your marketing campaigns in 2015. Register by 31 October to take advantage of Early Bird Rates.