LONDON » British bookshops opened their doors early today and some grown-up Harry Potter fans lined up overnight as J.K. Rowling launched her long-anticipated first book for adults, "The Casual Vacancy."

The lines were shorter and the wizard costumes missing, but the book was published to some of the same fanfare that greeted each Potter tome, with stores wheeling out crates of the books precisely at 8 a.m. as part of a finely honed marketing strategy.

Published five years after the release of the last book in the boy wizard saga, "The Casual Vacancy" is already at No. 1 on Amazon’s U.S. chart, and bookmaker William Hill put 2/1 odds on it outselling "Harry Potter and the Deathly Hallows," which shifted 2.6 million copies in Britain on its first day.

Many of the early buyers were Harry Potter fans who, like the author, have moved on to more adult fare.

"I just like how much excitement there is about a book," said 23-year-old Grace Proctor, a "massive" Potter fan who was first to buy the book at one London store.

"I think there are going to be people who will hate it just because they can hate it," she said. "But she’s such an amazing writer, I don’t think she can go wrong."

A story of ambition, envy and rivalry set in the fictional English village of Pagford, the novel recounts the civic warfare sparked when the unexpected death of a town official leaves a vacancy on the governing body. Characters set on a collision course range from the affluent lawyer Miles Mollison to the Weedons, a ramshackle clan living in The Fields, the run-down housing project on the edge of town.

Rowling has said she was aiming for Dickensian sweep in the multi-character saga, whose doses of sex, satire and swearing mark a distinct departure from wholesome Harry.

Reviews have been mixed. The Associated Press judged it a challenging but rewarding read full of emotion and heart. AP’s Deepti Hajela said that while its troubled characters mean "this isn’t a book that’s easy to fall in love with … But what could have been an unreadable story becomes something else in Rowling’s hands, thanks to her gift of being able to make her characters complex and really, just human."

The Guardian newspaper’s reviewer, Theo Tait, said it was "no masterpiece, but it’s not bad at all: intelligent, workmanlike, and often funny."

The Independent’s Boyd Tonkin found the sometimes "long-winded and laborious" writing soared when Rowling focused on her teenage characters.

Others, though, felt the lack of likable characters might alienate readers, and Daily Mail reviewer Jan Moir slammed Rowling’s stark focus on Pagford’s haves and have-nots as the work of a "left-leaning demagogue" painting "a bleak and rather one-sided vision of life in modern England."

It’s likely nothing Rowling publishes will ever match the success of the Potter books, which have sold more than 450 million copies around the world.

But booksellers are confident "The Casual Vacancy" will be one of the year’s best-sellers, whatever reviewers say.

"A lot of children have grown up with Harry Potter. They’re now adults who love books," said Susan Sinclair, divisional manager for the Foyles bookstore chain.

"I think it’s going to be a really big seller at Christmas. It’ll be an easy gift — but also a good one."