検索とソーシャル・グラフ

...Searches related to news, blog posts, funny videos, etc. are mostly a loss leaders for Google. Google’s real business is selling ads for plane tickets, dvd players, and malpractice lawyers. (I realize this might be depressing to some internet idealists, but it’s a reality). Online advertising revenue is directly correlated with finding users who have purchasing intent. Google’s true primary competitive threats are product-related sites, especially Amazon. As it gets harder to find a washing machine on Google, people will skip search and go directly to Amazon and other product-related sites.

This is not to say that the links shared on social networks can’t be extremely valuable. But most likely they will be valuable as critical inputs to better search-ranking algorithms...