the search for success 65 Search engines don't index every one of those trillion URLs, of course. Many contain similar or duplicate information, or aren't really relevant to search (think of a dynamically generated online event calendar, for example, with links to `next day' and `previous day' ­ in theory you could keep clicking forever, but only pages containing event information are of any relevance in search results), so some don't make it into the index. We don't know how many pages there are on the web, or, for that matter, how many are stored in the search engines' indices (information that's rarely volunteered), but it's safe to assume that we're dealing with some very big numbers. The list of results for any given search query, which often contains many millions of pages, is then run through the search engine's complex ranking algorithms: special programs that use a variety of closely guarded proprie- tary formulas to `score' a site's relevance to the user's original query. The output is then sorted in order of relevance and presented to the user in the SERPs. Search engines process a huge volume of searches, scanning billions of items and delivering pages of relevant, ranked results in a fraction of a second. To the user the process seems quick, straightforward and seamless; but there's a lot going on behind the scenes. Google and Bing (which, following a 2010 agreement between Yahoo! and Microsoft, now also powers Yahoo! search results) are running some of the most complex and demanding computer applications in the world. optimizing your site for the engines To many, SEO appears to be something of an arcane art. It's a world that's shrouded in high-tech mystery, a complicated world full of secrets that mere mortals haven't a hope of understanding. But according to leading UK-based SEO expert Jason Duke, of Strange Logic, there are no real secrets in SEO. `The web is a very open place,' he says. `If a site is riding high in the search engine listings, then you can, with enough persistence, get to see why it ranks so well. Replicate it, and you can join them ­ it really is as simple as that.' Matt McGee, an SEO expert who specializes in advising small businesses ( www.smallbusinesssem.com ), concurs with Jason's sentiments. In an inter- view on the `Your SEO Plan' ( www.yourseoplan.com ) blog in December 2006, Matt says, `SEO is not rocket science. It's simple, but it's not easy. There's a difference! There's a small set of basic rules that apply to any web page or website, whether you're a small business or not. Your site has to be crawlable, your content has to be good ­ and I'd include things like page titles, keyword use, etc under the umbrella of "content" ­ and you need quality, relevant inbound links. That applies to everyone.' One of the best places to start for tips on improving your site's ranking with the search engines is with the search engines' own guidelines, tips and resources for website owners. See Table 4.1