“Broadway has never been broader. It’s not just for gays anymore!” sang a purple polyester-suited Neil Patrick Harris, the host of Sunday night’s 65th Annual Tony Awards, as performers with flawless coifs high-kicked around him.

Broadway certainly has reason to celebrate. The Great White Way raked in just under $1.1 billion during its 2010-2011, 53-week season, making it the highest grossing in Broadway’s history.

What did they do right? For one thing, this year’s season ran a week longer than usual (every seven years, shows run for 53 weeks, rather than the normal 52). But even without those extra few days, this was still the “highest grossing of any season on record,” according to The Broadway League, a trade association for Broadway producers and theater owners.

But can we really tie Broadway’s successful run to its broadening horizons?

Listen to the lyrics from the opening number at the Tonys, and it’s clear that Broadway has diversified. “There used to be three kinds of shows,” says Charlotte St. Martin, executive director of The Broadway League. “There was the musical, the comedic play, and the serious play. Now, there’s edgier material that appeals to the young demographic… There was a youthful mischief on Broadway this past year.”

Youthful mischief aside, the hoopla around Broadway’s “best year ever!” may have less to do with America’s newfound appreciation for the stage and more to do with tourism. According to the League’s demographic study for the 2009-2010 season, 63% of all Broadway tickets were purchased by tourists, and 21% of those tourists came from outside the U.S. The previous season saw similar numbers.

NYC & Company, the city’s official tourism marketing organization, reports that in 2010, 48.7 million tourists visited New York. In 2009, it was 45.6 million, and in 2008, 47 million. Broadway’s sales mirrored this pattern: in 2010, 12.11 million people attended shows; in 2009, 11.88 million; in 2008, 12.88 million. (These numbers are based on the calendar season — January to December — not the Broadway season, which runs from June to May.)

When more tourists head to New York City, Broadway sells more tickets. This season had an undeniable vivacity with its spread of new productions, but St. Martin warns, “[Success] is not cookie cutter… There’s no magic formula.”

The producers, the theaters, and the Broadway community invest in plays they believe will appeal to their (tourist-heavy) audiences and cross their fingers, hoping for a win.

The content behind the flashing marquees — from the traditional to the star-studded to the profanity-filled — brought a flurry of much-needed media attention to Broadway over the past few months.

While it’s understandable to discuss Broadway’s impressive financial season and its new shows in the same breath (and many have done just that), were the masses really flocking to New York to see the new, attention grabbing shows?

During the 2009-10 Broadway season, tourists accounted for 71% of the sales of long-running shows (1+ years) and 62% of medium-running performances (4-12 months). Tourists bought 48% of the tickets for new shows — an impressive share, but much smaller than the other two categories.

Long-running shows historically top Broadway’s “highest gross” list, and this year was no different. Wicked, The Lion King, Jersey Boys, and Billy Elliot: The Musical — all long-running shows — brought in the largest financial returns out of all shows during the 2010-2011 season. And while Book of Mormon — a new show — has found a stable spot on the top-grossing lists in recent weeks, it’s often sandwiched between the veterans.

Broadway needs tourists to flourish, but it’s impossible to rely on just that demographic. Audience tastes vary, as do tourist visits. And new shows may keep locals interested in the theater, but they’re not the main draw for out-of-towners.

“One out of five shows recoups its investment, so there’s something innately magical about someone who would invest in a project with a 20% success rate. These are artists, gambling men,” Charlotte St. Martin says.

In Martin’s mind, there is no science to the business of Broadway. “It’s a combination of materials, content, a good script, and luck.”

This year’s Tony Awards brought in 6.95 million viewers on Sunday night, just a little less than last year’s 7 million viewers (far less than the 24 million that watched the NBA Finals). Broadway remains a relatively niche industry. And while fierce new shows might create an air of excitement, the Great White Way lives and dies on its veteran shows and its veteran-show-loving visitors.