Nick Denton has a smart critique of Google News: “It discriminates against an exclusive, which is perverse. A story exclusive to one source — the New York Times scoop on US war plans, for instance — will rank low. While a standard calendar-driven wire service story — reported everywhere, without any great enthusiasm — scores highly.”

This gets to the nub of Google’s power, and also its biggest shortcoming. You can’t beat the convenience of ranking pages by popularity. But you also have to believe that popularity is a good index of quality.