A report from Google has counted there are more than one trillion unique URLs, as opposed to domain names, reports IDG. Google openly admit they do not index every one of these pages "many of them are similar to each other, or represent auto-generated content ... that isn't very useful to searchers," wrote Jesse Alpert and Nissan Hajaj, software engineers in Google's Web Search Infrastructure Team.
To read the IDG report, see www.networkworld.com/news/2008/072508-google-counts-more-than-1.html.