SEO techniques can be classified into two broad categories: techniques that search engine companies recommend as part of good design ("white hat"), and those techniques of which search engines do not approve ("black hat"). The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO. White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.
Knowing which pages visitors go to directly gives you an opportunity to design those pages so they accurately and quickly address visitors' needs. For example, if you sell clothing and your new-arrivals page is a popular destination, you want to be sure the content is always fresh, and you want to provide easy access to the full department represented by each new item. Who wants to see the same items week after week on a page that is supposed to represent the cutting edge of your inventory? And if you're featuring a new raincoat or bathing suit, you want to let visitors also easily see your whole line of raincoats or bathing suits."
Remember when you used to rely solely on search engines for traffic? Remember when you worked on SEO and lived and died by your placement in Google? Were you #1? Assured success. Well, okay, maybe not assured. Success only came if the keywords were relevant to your site users, but it was the only real roadmap to generating site traffic and revenue.