ICoupon Blog did an A/B split test of a landing page with and without a security icon. And surprisingly the page without the security badge increased conversions by 400%.
What the ICoupon Blog tested was whether having a large ‘Secure’ icon in the sidebar would help with our conversion rate. They thought the icon would help because it would push down other (distracting) text in the sidebar.
In nutshell, in this particular case, it looks like the secure icon distracted the visitor from the main focus of the page.
Do you split test the security icons on your landing pages?