When I was doing my MSc dissertation (developing a Search Engine), I used figures from "Computing" magazine which claimed that there were "around 800 million publicly available pages, of which the best search engines can only index about 16%". (Issue dated 29 July 1999). (It also claimed that in 1997 there were about 320 million web pages.) Note, these are publicly available pages. Think of all the private intranet pages too and the total goes much higher. If you consider that newspaper/broadcasting websites store their information in new pages everyday, the numbers are rocketing up. And I presume each new Mudcat thread constitutes a whole new page!