The Sports Illustrated Swimsuit Issue hit newstands today .

Blonde bombshell Kate Upton graces the cover for the second year in a row, which should excite tons of readers who giddily await the glossy's once-a-year release featuring page after page of barely-dressed models on beaches.

But for Time Inc. , the publication's parent company, the Swimsuit Issue means something more: a billion-dollar business that's bigger than the sports magazine that spawned it.

Since becoming a stand-alone issue in 1997, the magazine has become "one of Time Inc.’s biggest revenue drivers over the years, bringing in more than $1 billion," according to Forbes.

Here's how the magazine became its own industry:

• The first Sports Illustrated swimsuit edition debuted on Jan. 20, 1964, as a five-page supplement. It was designed by then-editor, Andre Laguerre to increase readership during the winter lull between popular sports seasons. The premier cover featured Babette March in a white two-piece.

• Fashion reporter Jule Campbell was chosen as SI's first swimsuit editor. During her 31-year reign from 1965 to 1996, Campbell transformed the publication from a provocative glossy featuring a few bikini-clad women into a commercial behemoth.

• In 1997, SI's swimsuit edition received special-issue status. It has since become the single best-selling issue in Time Inc.'s magazine franchise .

• In 2005, the swimsuit issue brought in an estimated $35 million in ad sales ; Today It generates 7 percent of Sports Illustrated's annual revenue , SI editor Terry McDonnell told USA Today.

• The swimsuit issue isn't just a boon to advertisers — bikini and jewelry designers whose items are featured in the special issue also experience a major boost in sales.

• Regular Sports Illustrated has more than 3 million subscribers and is read by about 23 million people a week.

• The swimsuit issue traditionally sells more than 1 million copies on newstands (about 10 to 15 times as much as regular SI). Last year, consumers forked over $6.99 to get their hands on the popular glossy.

• In 1983, SI rolled out its first swimsuit calendar. This was followed by a television documentary of Sports Illustrated's 25th Anniversary Swimsuit Issue. Over the next two decades, a compilation of videos, TV specials, trading cards, cell phone screen savers, and other secondary products have contributed to an additional $10 million in revenue , according to CNN Money.

• The 1989 Swimsuit Edition, which celebrated the publication's 25th Anniversary and featured Kathy Ireland, is the best-selling issue of all time.

• In 2011, Sports Illustrated and Sony released a half-hour "Swimsuit in 3-D" video, exclusively for PlayStation 3 owners available through the PlayStation store.

• In February 2011, Sport Illustrated also began selling its first ever digital subscriptions, available on Google Android, which launched in tandem with the paper magazine.

• For the first time last year, the Swimsuit Issue was offered on four digital platforms, including a tablet edition and iPhone app with 360-views of bodypainted athletes. The magazine's release was also accompanied by a two-day music festival in Las Vegas, Sports Illustrated Swimsuit Beauties & Beats, showcasing emerging indie bands that are featured in the 2012 Swimsuit Issue.

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