It used to be that when a Broadway show booked an out-of-town tryout, it actually went out of town.

Not anymore. The world premiere of Rialto-targeted musical “Honeymoon in Vegas” premieres this fall at the Paper Mill Playhouse in Millburn, N.J. — less than a half-hour ride from midtown Gotham — and that proximity is the mark of a major shift in the way commercial producers think about legit creative development in the new media age.

“Ten years ago, we all wanted to go out of town to hide while we worked on our show,” said Roy Gabay, a lead commercial producer attached to “Honeymoon” alongside Dena Hammerstein and Dan Farah, among others. “With social media the way it is now, there is no hiding.”

“Honeymoon in Vegas” is the latest in a string of Broadway titles to bow at Paper Mill, the 75-year-old nonprofit. “Newsies” preemed there in 2011 before strong response prompted Disney Theatrical Prods. to move the show to Broadway. In 2010, the 25th anniversary tour of “Les Miserables” debuted there — in the same staging that producer Cameron Mackintosh recently slated for a Main Stem engagement in 2014.

In the past, Paper Mill had been considered far too close to Gotham to develop new titles, which producers preferred to nurture in some faraway, cloistered city shielded from the industry’s prying eyes.

But with Twitter and Facebook now available for local theatergoers to broadcast the moment-by-moment developments of a production, what happens out of town never stays out of town — and Paper Mill is reaping the benefits of the shift.

“The stumbling block for many years was the proximity to New York,” said Paper Mill’s producing a.d. Mark S. Hoebee. “Now it’s done a complete 180, and it’s become very attractive.”

Producers still take tryouts out of town, of course, such as “Kinky Boots,” the incoming Broadway musical that preemed in Chicago, or “Big Fish,” soon to bow in the Windy City before moving to New York later this year. But as distance becomes less of a compelling factor, Paper Mill can offer other advantages.

At the nearby nonprofit, New York creatives can work on a new show and still live at home, thereby cutting the costs of putting up talent out of town. For a Gotham-based commercial producer, it also becomes a lot easier to swing by to a check out a matinee — which can turn into a weekend-long ordeal if a show’s in California.

In addition, the proportions of Paper Mill’s 1200-seat venue provide a comparable model for most of the Broadway or road houses a production might encounter in the future, allowing a lot of the design work at Paper Mill to carry over to subsequent incarnations.

Such advantages are all in addition to the nonprofit producing infrastructure Paper Mill — with an annual operating budget of about $15 million and a subscriber base of more than 19,000 — brings to the table. As was the case with “Newsies,” Paper Mill is the producer of the world premiere of “Honeymoon,” enhanced by funds from the attached commercial entities. A brewing project can also benefit from the theater’s artistic staff, on hand to help hone a show.

For Paper Mill, the reward is a high-profile production with a recognizable star, adding a little pre-Broadway prestige to the company’s 75th anniversary season. Tony Danza toplines “Honeymoon in Vegas,” the new musical based on the 1992 Castle Rock comedy with a book by film scribe Andrew Bergman and score by Jason Robert Brown (“Parade”). Gary Griffin (“The Color Purple”) directs.

Next season, it’s not just “Honeymoon” that Gotham legiters are keeping an eye on. According to Hoebee, there’s also a commercial producer attached to Off Broadway alum “The Other Josh Cohen,” another entry in Paper Mill’s 2013-14 season along with productions of “South Pacific,” “Grease” and “Oliver!”

“Honeymoon” bows at Paper Mill Sept. 26-Oct. 27, with the details of its future commercial life to be nailed down in the wake of the musical’s initial reception.