Yesterday Oprah Winfrey canceled an already taped episode about the tenth anniversary of the Columbine school shooting, twittering that the episode "focused too much on killers."

Over at Portfolio, various publishing experts weighed in on what the canceled show would mean for Dave Cullen--the author scheduled to talk about his book, "Columbine." It's an interesting look at Winfrey's bookselling powers during the recession.

Check it out: "One publishing-industry expert who didn't wish to be quoted estimated that the publisher would most likely have ordered another 50,000 or so copies in expectation of 'The Oprah Effect.' But another, Bookreporter.com president Carol Fitzgerald, questioned whether the order would have been increased that much. 'I don't know if anybody prints extra for anything these days,' she said. 'The business is so fluky right now.'"