Seems like people form first impressions of web design – whether or not they like the design – within 50 milliseconds! 50 milliseconds? Isn’t it amazing how we’re quick to judge?
The coverage of this research suggested that key ingredients of a good-looking website should "be strictly limited, perhaps to a single eye-catching image."
Online marketers and web designers release a collective: < gulp! >
Story at http://www.nature.com/news/2006/060109/full/060109-13.html
Seth Palmer

“Caudron suggests that the amount of graphics on the page should be strictly limited, perhaps to a single eye-catching image.”
That’s quite a subjective blanket statement. It does not consider sites which are content-based and need to offer users a variety of options.
For example a shopping site with multiple brands and a wide selection of categorized products… which if presented with one single image might give the impression that there isn’t much product selection.
This research was done by a Canadian organization.