With their acquisition of Pyra and new Content-Targeted Advertising offering, it should be apparent that Google is not a search company. What they are exactly is unclear, but their biggest asset is: a highly annotated map of the web.
Search engines gather pages without regard to their positions in cyberspace. With their map, Google not only has the pages, but they know how those pages are related to each other. If you take a look at their offerings, many rely on this map in one way or another:
- Search: Pages are returned based on how important they are (i.e. their positions relative to important sites) for a given query.
- News: A submap consisting of just news sites is divided into sections (tech, sports, etc.) and stories within those sections are grouped together by specific topic.
- Content-Targeted Advertising: Since Google's map is annotated and they know which pages are more important than other, they can provide highly targeted page-specific ads and determine accurate pricing without having to audit each site's traffic for their customers.
- Web Directory: Same idea as search...ranking due to importance.
And now with Blogger, they can watch the people who are building the pages that comprise Google's map to gain knowledge about their map that they can't get from scraping.
Google's money won't be made with search...that's small peanuts compared to selling access to the world's biggest, best, and most cleverly-utilized map of the web. And I have a feeling that they know this (Google is famously tight-lipped about what kind of company they are and how, exactly, they plan to make money), but they're just not letting on lest other people get ideas about trying to compete with them.