Web Usability Aside -- Important stuff on the left, please

I do some work on my company's corporate Intranet, and usability is paramount, especially if you're looking to drive engagement and productivity across a population of users.

Of course, we all know that the most important elements of any page should go "above the fold," i.e. where people don't have to scroll down to see it, but perhaps we're best served by placing the revenue-driving, engagement-promoting, productivity-increasing elements on the upper left.

Just a note from usability guru, Jakob Nielsen, on his usability blog:

"Web users spend 69% of their time viewing the left half of the page and 30% viewing the right half. A conventional layout is thus more likely to make sites profitable."

Nielsen takes time to discuss how this finding breaks down in "right-to-left-reading sites" like in Arabic or Hebrew, but I can't help but wonder whether culture, gender, or age plays some role in how folks dally on sites.