[koenbok]

(We make checkoutapp.com)

We test, but we always put emotional arguments ("it looks better") above scientific data when it comes down to design. It's impossible to prove what gives better results in the long-term, but we would hate putting something online that doesn't look good to us. One thing I can really notice is that customers always tell us that our website/style stood out while they were evaluating the product, so it seems to work well for us.