Design factors that can make a difference ...
"I admit, it’s a provocative headline. But it’s true.
However compelling the message, however great the copy, however strong the sales argument… the way a page is designed will have a dramatic impact on conversion rates, for better or for worse.
Here’s how design choice can make a difference
Here are just a few of the design elements we have found can make a significant difference to the performance of a web page:
- The position and color of the primary call to action
- Position on the page of testimonials, if used
- Whether linked elements are in text or as images
- The amount of “white space” on a page, giving the content space to “breathe”
- The position and prominence of the main heading
- The number of columns used on the page
- The number of visual elements competing for attention
- The age, sex and appearance of someone in a photo"
continued ... (Via A List Apart) 
Results from three webpage versions.