The major issue was gaining entry to the beach, particularly between 4 and 6 p.m., when Shelton went on stage and a second wave of people flocked to the area.
With only one entrance, lines stretched for five blocks 30 minutes into the concert, and many fans gave up and listened from the Boardwalk.
Sunday, for Lady Antebellum, there will be multiple entrances.
"Everyone will still go through security, but this will get people off the Boardwalk and onto the beach faster," Guaracino said.
Official numbers were not available, but Guaracino said the city's hotels and casinos reported upticks in revenue.
Tickets were assigned by zone, and because people were allowed into the zones (beginning closest to the stage) on a first-come, first-served basis, fans came as early as 10 a.m. to claim good spots.
But there were complaints that some people were let into prime stage-viewing areas later. Officials confirmed that some fans were upgraded from the back. "People who looked really country and were really into it - we went to the back and said, 'There's room up front, would you like to go?' But it was orderly," he said.
Exiting the beach was expected to take 45 minutes, but since Shelton played 15 minutes later than planned, the exodus happened partly in the dark.
"It was scary, to be honest - there didn't seem to be enough security to handle that many people," said Eric Siegel, 24, of Pine Bush, N.Y., who attended with his girlfriend. "People were climbing over fences. It took us 40 minutes to get out."
Guaracino said concert organizers for Sunday had already asked performers to stick to their set time. He also expects a slightly smaller crowd.
Sunday's forecast shows a chance of thunderstorms, but the show will go on rain or shine.
Other complaints included price gouging at parking garages - Caesars and Bally's charged $50 - spotty cell service, and long wait times for food and drink vendors.
Guaracino had a silver lining for that, too: "This was a beer-drinking crowd," he said. "And if people had to wait in line for beer, that's a good thing, because that meant local vendors made money."