As web developers, we spend a lot of time helping our clients figure out what’s most important so we can put it above the fold (meaning viewable on an “average” configuration without scrolling). This is incredibly important, since people spend about 80% of their time looking at information above the fold.

But horizontal placement is also important. According to user interface expert Jakob Nielson’s research, Web users spend 69% of their time viewing the left half of the page and 30% viewing the right half. This is good to know when designing a website, since it makes a more conventional layout more profitable.

Here are some things to consider:

• Keep navigation all the way to the left. This is where people look to find a list of current options.
• Keep the main content a bit further in from the left.
• The most important stuff should be showcased between one-third and halfway across the page. This is where users focus their attention the most.
• Keep secondary content to the right. It won't be seen as much here, but that's okay — not everything can get top billing, and you need a place to put less-important material. 

Of course, rules are made to be broken, but if you know the rules, you will have a better shot at a profitable website.