Following rapidly on my recent blog post about what Apple’s search strategy might be (http://www.viking2917.com/is-apple-building-a-search-engine-should-they/), they’ve bought Siri. A full frontal assault on Google is futile, but Facebook and Apple are both finding ways to attack Google in a flanking manner. Apple is doing it through entertainment, apps, rich advertising (Quattro acquisition), and task-centric, information-rich applications (Siri). Facebook is plastering “Like” buttons all over the internet, thus gaining very valuable information – “Like” is essentially a human-driven relevance signal, one that is much more direct and personalized than the algorithmic PageRank of Google, which relies on computing links and link values. Facebook’s “like” button gives them a simple popularity metric – how long before they use that to build a new kind of search & information access tool? Certainly such a metric is gamable, but at scale, it may not matter….