A: This is a very commonly asked question. A website must have certain technical/mathematical considerations for the main content of the page. You'll notice that most web pages have "channels" on either side of the middle content section.
The content or "middle section" of your web page has been programmed to always be in the absolute center of the browser window. You are, most likely, viewing your new web page on a bigger/more sophisticated screen than the average person. The average computer user (about 75% of most computer users) have a screen size of 1024 pixels wide X 768 pixels high. That translates to only about 14 inches wide X 10 Inches high. That's very small compared to more professional/bigger screens. To make matters complicated, the average laptop user has only a 12 inch wide screen. To make matters even more complicated, most people haphazardly download and install browser extensions and add-ons (Yahoo toolbar, virus scanning toolbars, etc) that take up even more visible room in a browser window. So, I tend to err on the side of caution when constructing your page. I want to make sure that your main content can be seen easily by the highest percentage of people. People who encounter a site that is beyond their screen's size constraints, statistically, get confused, frustrated and often just surf to another site.