Monday nights are usually among the slowest at Positano Restaurant in Wayne. But when a Pokemon suddenly showed up on the counter of the pizzeria — or, to be precise, the new Pokemon Go app generated a character in the restaurant that players could see on their phones — the staff of Positano decided to share the news on the restaurant’s Facebook page.

Pokémon has been spotted hanging at Positano!! Posted by Positano Restaurant and Pizzeria on Monday, July 11, 2016

Within an hour, owner Joe Catalano said there were "car loads of people" flooding the restaurant.

"They said, 'We're here for Pokemon!' We didn't tell them they had to stay and buy food, but many of them did," Catalano said. Before the night was over, the restaurant ended up posting some of its highest sales for a Monday in recent memory.

For those who have spent the last few days in deep hibernation, Pokemon Go is a geolocation-based game whose popularity has quickly swept the nation. Since its release last week, Nintendo (which owns Pokemon) has seen its stock price soar and, according to Rolling Stone, the app is set to overtake social media giant Twitter in the next few days in terms of user engagement. Niantic, the creator of the app, hasn’t released official usage numbers.

The app has been criticized for everything from creating public safety hazards to invading users' privacy to encouraging tasteless behavior (the Holocaust Museum in Washington D.C. had to issue a stern warning to visitors to stop playing the game inside the building).

But at least in New Jersey, there also appears to be an unexpected upside to the craze. Businesses that have been declared "Pokestops" or Pokemon gyms have seen rising sales and a sudden influx of new patrons. Even traditionally august institutions, such as museums, are trying to piggyback on Pokemon Go and use its success to boost their own admissions.

For Positano in Wayne, the restaurant just happens to be located in the the Point View Shopping Center, whose clock tower is one of the app’s Pokestops, places where Pokemon players can find loot, like Pokeballs and medicine. The stops, like the clock tower, are determined by Niantic’s portal database for Ingress, a massive, location-based online game.

The result was a modest economic windfall that Positano owner Catalano never could have anticipated.

"On a Monday at 7 p.m., we don't usually sell a lot of slices," he said. "But (this) night, we did."

(One of Catalano's deliverymen also had an encounter with Poke-mania -- he was stopped by a group of kids playing the game who told him there was a Pokemon in his car and they wanted to catch it.)

An angry Bulbasaur tries to evade capture. (Sydney Shaw | NJ Advance Media for NJ.com)

The pizzeria isn't the only New Jersey business that's seen an uptick in sales.

Sam's Bagel and Deli in Wayne has seen an increase of younger patrons since the game's release on July 6. That restaurant isn't a Pokestop, but the community center just around the corner is.

"We've got high school kids coming in and out of here like crazy, holding their phones up trying to catch Pokemon," server Jan Carlos said. "The place has been packed with them. It's honestly been awesome."

At the Jersey Shore, store workers also reported seeing particularly intense Poke-action — though couldn’t necessarily say if it was impacting their bottom lines.

"Since it seems to be determined by areas of high traffic, the entire shore is packed with Pokestops," said an employee answering the phone at The Chicken or The Egg in Beach Haven, who asked not to be identified. "We see a lot of people playing here, but it's hard to measure if the game is bringing in more customers, since we're always so busy anyway."

Given the elusive nature of how the Pokestops are determined — Niantic hasn’t fully explained exactly how the algorithms work — it’s often just a matter of luck which restaurants and stores end up reaping the benefits of being located near the Pokestops. But that hasn’t stopped some organizations from trying to take advantage of the popularity of the trend.

House of Independents, a live entertainment venue in Asbury Park, is a Pokestop, news of which the venue's promoter shared on Facebook Monday.

Just so you Pokemon lovers know.. House of Independents is a Pokemon Training Facility. Go beef up your pokemon! Posted by Christine Feola on Monday, July 11, 2016

Meanwhile, Montclair Art Museum posted on Facebook Wednesday morning that one of its outdoor exhibits, Allan Houser's "Earth Mother," is a Pokestop.

Are you a Pokémon Go trainer? Don't miss this Pokéstop at Allan Houser's "Earth Mother." #pokemongo Posted by Montclair Art Museum on Wednesday, July 13, 2016

"I got the idea to check out the game because I read an article about how it uses landmarks and historic sites as Pokestops," MAM Marketing and Communications Manager Catherine Mastrangelo said. "I found out that not only is our statue a Pokestop, but the museum itself is a Pokemon gym."

(Gyms are rarer than Pokestops and serve as locations where trainers can battle their Pokemon against another team's Pokemon. If this doesn't make sense to you, consult your children.)

While Mastrangelo hasn't yet noticed anyone visiting the museum specifically to catch Pokemon or go up against other trainers, she's hopeful her post will have an impact on the museum's attendance.

"It's a cool way (for us) to engage with this phenomenon," she said.

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Sydney Shaw may be reached at sshaw@njadvancemedia.com. Follow her on Twitter @SydneyLShaw. Find NJ.com on Facebook.