An eyetracking study recorded how users looked at thousands of Web pages including Google and Slashdot.
The study looked at how people navigate websites, search and react to advertising.
The summary is that a human eye scans a webpage like letter F. These results [similar to Google Heatmap] are depicted in the picture on the right side.
The areas where users looked the most are colored red; the yellow areas indicate fewer views, followed by the least-viewed blue areas. Gray areas didn't attract any fixations.
The results offer some useful hints for Web Designers and Bloggers showing Advertisments.
First, for effective layouts - don't place Google Ads [or other advertising banners] on the right sidebar as web users typically ignore that area.
Users scan a webpage in seconds and no one is going to read text word-by-word. Most are only going to read the first two paragraphs. In a few seconds, their eyes move at amazing speeds across your website’s words in a pattern that's very different from what you learned in school.
Therefore, try to highlight [use different font, increase font weight] the important lines to attract user attention. Make the initial paragraphs interesting to read.
Related: Read Google Adsense Tips
Read: F-Shaped Pattern For Reading Web Content
Source: DP Forums | The eyes have it