Server side includes speed up download times as the included file only needs to be downloaded once to be used on several pages . Style sheets also only need to be downloaded once. Using one means you don't have to specify style within the HTML page, which makes for a smaller html file size . If your web site is not user friendly , people will not return to it. It is return users who will buy your product or service , not a unique user who merely visits your site the once .
Good usability is found in easy to follow navigation and strong, simple site structure .
At any one time, the user should be able to reach any level of the site and clearly see where they are in the site's hierarchy. A well designed site should have a logical hierarchy of more detailed information as the user delves down into the site. The main home page to a site should have links to a variety of levels , usually in the form of a navigation panel. On subsequent pages , the user should be able to reach other pages of the same level as well as be able to go up to the previous level . In addition, make sure the page title , located in the head information of your HTML, shows the page title and where the page is in the site.