Often we will hear "I only need 5 pages". In fact, that may actually wind up as 10 -12 pages. One factor is related information. You don't want About Us information on the same page with products - it causes confusion with site visitors. You also don't want to have a page that is more than one and one-half screen lengths - the bottom information is rarely viewed. You may also want certain pages designated for unique information or search engine landing pages.