How big is the web? the short answer is very big indeed. Google recently reported that there are now  1,000,000,000,000 (trillion) unique URl`s. This is after removing all the duplicates and ignoring many auto generated URl`s. Google does not index all these pages and how many are useful is a whole different question which does not have an easy answer. But whichever way you look at it marketing your web pages is becoming more and more important.  SEO (Search Engine Optimisation) has moved from being a side issue when creating web sites and pages to being the first consideration when you first plan a web page. ie Who is this page for ? What keywords will they be using ?