I'm just reading through a patent application on how a search engine could build a primary and secondary index based on phrases rather than keywords.
In the introduction the author (who we can safely place at Mountain View) estimates that there are currently 200 billion pages on the Internet today. She says the best search engines only index between 6 and 8 billion pages.
What a difference, huh? Statistically your home page and this blog post has between a 3% and 4% chance of being indexed by a search engine.