Four Questions for Facebook's Graph Search

Facebook’s (FB)graph search is going live for hundreds of millions of English-speaking users today, the first serious option for searching a social-media site that blocks Google’s (GOOG) access to much of its data. Facebook claims its first foray into a powerful search tool will be a boon for its users, who will then stay on the website longer—and that, in turn, will be a boon to its advertisers. Everybody wins.