One of Atlantic City's newest attractions may be free, but business leaders hope it will be a boon for local merchants and an important piece of the resort's new marketing strategy.

The attraction, a 3D sound and light show, debuted July 4 at Boardwalk Hall, and will be on display permanently on the façade of the historic venue. The projection show is one of the latest exhibits at the Boardwalk as state officials and casino executives work to broaden the appeal of the struggling city.

Joseph Kelly, president of the Greater Atlantic City Chamber of Commerce, said the display drew large crowds when it premiered Wednesday, which could only benefit the nearby food vendors, retailers and specialty stores. He said he expects "you're going to have a lot of folks simply out for a walk on the Boardwalk, coming back from dinner or doing some shopping, and they're going to stumble on this — which I think is great."

"It's kind of value added. They're there to do a lot of other things, and now you've exceeded their expectations," Kelly said. "And I think a lot of people will be surprised by it, especially in the beginning."

He said the show appeared to draw guests from the Boardwalk casino hotels, a trend that advocates hope will continue as word of the attraction spreads.

"One of our strategies is to generate overnight visits," said Jeff Guaracino, a spokesman for the Atlantic City Alliance, the nonprofit marketing group created by the city's casino industry. "The city is a very popular day trip destination, and our goal is to get people to stay longer, spend more while they're there and experience more of what the city has to offer."

The projection show, which is produced by the Montreal-based Moment Factory, opens by making the 83-year-old Boardwalk Hall appear to crumble. The show runs nightly and last about nine minutes.