NEW YORK (AP) – Laurence J. Kirshbaum, the former head of Warner Books, remembers publishing one of the biggest sensations of its time: Alexandra Ripley’s “Scarlett,” the authorized sequel to Margaret Mitchell’s “Gone With the Wind.”

Ripley’s novel, with its answer to a decades-old tease – whether Scarlett and Rhett end up together – was a guaranteed, instant best seller, an object of fascination awaited by millions. And it deserved the fullest first printing that the market could handle, in 1991: 500,000 copies.

“It made sense at that level,” says Kirshbaum, now a literary agent, who added that printing any more books right away would have been “unreasonable.”

The rollout for the final Harry Potter book, “Harry Potter and the Deathly Hallows,” makes the fuss for “Scarlett” look primitive. Potter’s first printing was 12 million. Its sales after the first hour exceeded the first printing of “Scarlett.” After 24 hours, worldwide sales had topped 10 million, with 8.3 million in the United States alone.

But the numbers do more than capture the special appeal of “Deathly Hallows”: They reflect how the market has changed. Production and communication systems were far slower at the time of “Scarlett,” did not exist, superstores were only getting started and price clubs weren’t selling nearly as many books as they are now.

No book before “Deathly Hallows” sold so quickly. No book could have.

“With ‘Potter,’ you have almost a perfect storm of events,” says Steve Ross, president and publisher of Collins, a division of HarperCollins. “You have changes in technology and capacity, the synergy that worked so effectively between the books and the movies, and, most importantly, … they were books of startling quality.”

“I surely would hesitate before trying to do something like 12 million copies for Dan Brown’s next book, but thanks largely to ‘Potter,’ we can think about numbers we wouldn’t have imagined before,” says Stephen Rubin, president and publisher of the Broadway Doubleday Publishing Group, which released the mega-selling “The Da Vinci Code.”

Scholastic benefited from technology that wasn’t in wide use before the 1990s. Greater access to e-mail meant that lengthy, complex documents could be transmitted instantly, and legibly, unlike a fax or letter. Satellite tracking allowed the publisher to know the exact location of every delivery truck.

“We could see that a trailer was stuck in traffic and running two hours late,” Andy Yablin, Scholastic vice president of global logistics says.

“We could then ring up a store and tell them when to expect the delivery. In the old days, we had to wait to hear from the store.”

Creating Potter demand was easy; a brief announcement of the release date, July 21, immediately sent “Deathly Hallows” to the top of best seller lists. Supply was the challenge, coordinated in the United States by a trio at Scholastic Inc. who worked together on the last four Potter books: Ed Swart, director of operations and distribution; Andy Yablin, vice president of global logistics; and Francine Colaneri, vice president of manufacturing and corporate purchasing.

The release of “Deathly Hallows” was a timed worldwide gala, with the guest of honor embargoed until midnight. Scholastic’s planning began at least a year ago, even before Rowling had finished the book, when Colaneri began consulting with printers about possible production dates, getting a sense of when they could handle such an unprecedented order.

Colaneri would not say exactly when Rowling turned in her manuscript – the publication date was announced in February. But she did say that thanks to digital scanning (instead of using film, under the old system), the time spent getting a template ready was cut in half from what it would have been a decade ago – “a matter of weeks,” she says of the current pace.

Book production itself was accelerated, Colaneri says. Before Potter, lengthy hardcovers had to pass through binding equipment twice and then were joined together. Starting with the fifth Potter, the 600-plus-page “Harry Potter and the Order of the Phoenix,” manufacturers altered their presses to allow the entire text through at one time.

“That’s something that happened because of Potter,” Colaneri says.

Since the first Potter book came out, in 1997, every aspect of the business – from shipments to retailing – has consolidated and expanded. and Barnes & Noble each received more than 1 million pre-orders, unimaginable a decade ago. There are fewer (but larger) printing companies, truck carriers and wholesalers.

“From strictly a distribution perspective, fewer distributors or distribution center delivery destinations at increased volumes per destination is clearly more efficient,” says Swart, who added that “It should be remembered that the early Harry Potter books were first sold and embraced by the independents and the traditional bookstore chains, and only after they attained their eventual popularity were they picked up by the wider distribution network.”

The numbers for “Deathly Hallows” were historic for any book, but especially for hardcovers. Random House, Inc. spokesman Stuart Applebaum was a publicist in the 1970s for Bantam Books, a leading paperback publisher, when it had enormous success with “The Exorcist” and “Jaws.”

Helped by blockbuster movie adaptations, both books sold millions of copies, including at supermarkets and other nontraditional outlets. But paperbacks – smaller and cheaper – were distributed far more widely at the time than hardcovers. And they sold millions over a period of months, not hours.

“It wasn’t conceivable for a hardcover book to have that kind of sales, even for a book as sought after as “Jaws,”‘ Applebaum says. “At that time, the mass market paperback was the format for multimillion sellers. But the mass merchandisers weren’t selling as many books, and at the same velocity, as they do today.”

A decade ago, the maximum first printing for a hardcover would have been about 1 million or 2 million, for a new John Grisham or Stephen King, says Laurie Brown, senior vice president of sales and marketing for Harcourt. Each new Potter effectively raised the roof – from 3.8 million copies for Book 4, “Harry Potter and the Goblet of Fire,” to 10.8 million for Book 6, “Harry Potter and the Half-Blood Prince,” to 12 million for “Deathly Hallows.”

“Everything has to be firing at full power, all the time, for something like Potter to work,” Brown says. “We all wonder whether there will be a “next’ Harry Potter, but one thing we learned from this is that each Harry that came out helped us practice for the next Harry.”

AP-ES-07-26-07 1802EDT