GUEST BOOK: Dorothea Benton Frank's homey novels about family life in South Carolina's Lowcountry - her latest, "Porch Lights," hits the hardcover fiction list at No. 5 - are the kind you're apt to discover on the bookshelf of a rented beach house, their swollen pages foxed and mildewed and maybe marked with a ring of vegetable oil, since Frank's Web site provides recipes for her characters" meals. Grilled chicken, fried bananas, lots of seafood. Like a good vacation rental, the site also includes a guest book, where visitors can enthuse about their time in Frank's world. "Love love love your books!" one fan wrote during a recent stay on Isle of Palms, S.C. Another sought fashion advice: "I've never been to a "real honest-to-goodness" book signing with a "real honest-to-goodness" author before," she wrote. What do people normally wear? But as with guest books everywhere, you can sometimes learn more than you want about prior visitors. "You missed the opportunity of a photo-op, perhaps of a lifetime," a man wrote after accompanying his wife and granddaughter to a recent Frank reading. "I'm the octogenarian who asked you to put your bare foot on the signing table so I could "suck your toes." " THE OPRAH EFFECT: After spending six weeks on the hardcover nonfiction list this spring, Cheryl Strayed's memoir, "Wild," retired comfortably to the reaches of the extended list. Then Oprah Winfrey came calling. Since "Wild" was chosen last month as the inaugural title in Oprah's Book Club 2.0, its sales have (unsurprisingly) jumped; this week, the book is at No. But what's good for Strayed isn't necessarily good for the publishing industry. According to Craig Garthwaite, an assistant professor at the Kellogg School of Management at Northwestern, who analyzed book sales over the 15 years of the original Oprah Book Club, aggregate fiction sales actually declined whenever Winfrey recommended a particular title - possibly because her audience stopped buying easier books as they worked their way through Tolstoy or Toni Morrison. In other words, quality went up but quantity went down. "The results suggest there's a fixed market of readers," Garthwaite said by phone from his office outside Chicago. Oprah isn't bringing new readers into publishing; she's just shifting around people who were already participating in the market. And in that situation, there are always going to be winners and losers. FURST'S FAVES: The highest-ranked newcomer to this week's hardcover fiction list is Alan Furst's "Mission to Paris," at No. Like all of Furst's books, it dives deep into the atmosphere and politics of Europe on the cusp of World War II - subjects that also figure heavily in his personal reading, to judge from a book edited by J. Peder Zane, "The Top Ten: Writers Pick Their Favorite Books." I'm generally skeptical of lists like this (they're so well groomed, for one thing), but Furst fans looking to branch out could do worse than his favorites: 1) "Seven Pillars of Wisdom," by T. E. Lawrence. 2) "A Dance to the Music of Time," by Anthony Powell. 3) "Man's Fate," by André Malraux. 4) "Nightwood," by Djuna Barnes. 5) "Black Lamb and Grey Falcon," by Rebecca West. 6) "Darkness at Noon," by Arthur Koestler. 7) "Red Cavalry," by Isaac Babel. 8) "Homage to Catalonia," by George Orwell. 9) "The Radetzky March," by Joseph Roth. 10) "Kaputt," by Curzio Malaparte.