Website Response Times: Jakob Nielsen is harping on about page load times, and he revealed the results of a study which was pretty interesting. They had a page with a large graphical, promotional area at the top. It was programmed to load after an eight-second delay. They did an eye-tracking analysis on it.
The test participant in the top gaze plot fixated a few times within the big empty color block before the content downloaded, then spent the remaining time looking at the rest of the page. This user never looked at the big promotional space after it had rendered.
[…] Although 8 seconds might not seem like a big delay, it’s enough to kill this big promo that the company’s Web team probably spent weeks designing.
When there wasn’t a delay, eye-tracking analysis showed that the user spent quite a bit of time looking at the promotional area. So the delay alone completely negated all the design work that went into the promo area.