Sorry, that headline may have been a tad premature, as no official release date has yet been announced. Yesterday, however, author J.K. Rowling did finally release a title for the eagerly anticipated sixth volume in the wildly popular series, ending months of speculation. Fans will have to settle for the title alone -- Harry Potter and the Half-Blood Prince -- as scant few additional details were disclosed. The financial juggernaut that is the Harry Potter franchise just keeps on rolling.

The latest entry in the series -- Harry Potter and the Order of the Phoenix -- was an unprecedented success. Details of the book were guarded as tightly as a dark wizard in Azkaban, until pent-up demand on the novel's June 21 release date manifested into a phenomenon never before seen by American booksellers. Barnes & Noble (NYSE:BKS) sold nearly 900,000 copies within the first 24 hours -- a number that likely would have been higher had some stores not sold out. Within hours of the book's release, the company reported sales running on the order of 80 per second.

Sales at Borders (NYSE:BGP) were brisk as well, with 750,000 copies flying off bookshelves. There was no shortage of muggles checking their mailboxes that day either. (NASDAQ:AMZN) shattered sales records by shipping 1.3 million copies.

FedEx (NYSE:FDX) delivered 400,000 of the lengthy books to doorsteps across the country. All told, over 5 million copies were sold stateside (another 1.7 million in the UK) -- and that was just the very first day.

Collectively, the Harry Potter series has been a boon to publisher Scholastic (NASDAQ:SCHL), which has sold 250 million copies in 55 languages and 200 countries worldwide. The film version hasn't exactly been shabby either. Time Warner (NYSE:TWX) was immensely successful with the first two movies, which set box office records by raking in more than $1.8 billion worldwide. Prisoner of Azkaban has seen a sharp drop after an initial blockbuster opening weekend, and stands at $211.7 million to date. I suspect this is more an indication of mounting disappointment with the direction of new director Alfonso Cuaron -- who deviated drastically from the original course of the story -- than any waning interest in the franchise.

Whereas most series begin to crumble after the first few installments, this one is only getting stronger. If the trend continues, and I see no reason why it shouldn't, Harry Potter and the Half-Blood Prince will eclipse the already lofty sales records set by its predecessors and drive phenomenal traffic to stores and websites. When that magical day arrives, bookstores will see an undeniable boost to revenues. Be leery of investing based solely on the Hogwarts gang, however, as cutthroat pricing has historically kept many of the galleons (and dollars) from reaching the bottom line.

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Fool contributor Nathan Slaughter loves the Harry Potter novels, but was, as mentioned above, not thrilled with the Prisoner of Azkaban movie. He owns none of the companies listed.