On the Google Blog, they’ve been going on about the size of the Google index that’s grown at such great speed over the time of Google

The first Google index in 1998 already had 26 million pages, and by 2000 the Google index reached the one billion mark. Over the last eight years, we’ve seen a lot of big numbers about how much content is really out there. Recently, even our search engineers stopped in awe about just how big the web is these days — when our systems that process links on the web to find new content hit a milestone: 1 trillion (as in 1,000,000,000,000) unique URLs on the web at once!

Now, the whole thing about unique URLs they go on to qualify later, going on about a potential infinate quantity of links on the web, like ‘next month’ links and the like. Sure. But what abou the specifically google-tailored and subdomain cross-linked ‘SEO’ domains? I’m sure we can take out a margin of errors of 30% – 35% of auto-generated pages, links and domains.

But this example shows that the size of the web really depends on your definition of what’s a useful page, and there is no exact answer.

So they don’t index every page. Real content vs google-specific content…

I think it may be safe to simply agree that the index is big. Very big. With lots of lots of pages. There’s not much point in going on about the number.