As a blogger I of course see the value of short reviews of books. Sometimes just a couple of stars on a scale of 1 to 5 are useful if I know who put them there.
But as Thomas Mallon points out in a New York Times piece, "Highbrow, Middlebrow, Lowbrow --," there is still a valuable place for the old-fashioned book review.
"Criticism is the realm in which I’d prefer to see hierarchy abide. In the end, we’re all better off with a republic of letters, not a democracy. No amount of mindless “liking” or one-star customer-comment scorn can replace the lengthier, more considered critical judgments we used to have time to write and read. With everyone clamoring for recognition in the same ether — with everyone now, in effect, his own publisher — our judgments are ever less nuanced, ever more nasty or stupidly appreciative. Speed is imperative, and rumination is out. The brow that’s really in danger of disappearing is the furrowed one."