Ten of Korbin’s videos have been featured on ESPN, and he has been interviewed by news stations in Japan and Romania. His Instagram feed has nearly 65,000 followers.

Born with a disability, Korbin spent two and a half years doing physical therapy. “He finds so much joy and happiness in life, and we are so proud to share his good energy,” said his mother, Stephanie Jackson.

She said when Korbin arrives at school with his father, the older children surround him and ask to take selfies with the local celebrity. “When Korbin gets to high school, his following will be huge,” she said. “That Instagram just set him up for greatness.”

Korbin receives a lot of free stuff in the mail, and his parents often tag the brands in posts. Unsolicited, Ms. Jackson said, GoPro sent about $2,000 worth of camera equipment. Many sportswear companies send packages. Korbin’s feed frequently promotes Under Armour. “They send him boxes once a month,” his mother said. “It’s not a paper deal, it’s not a contract, they are inspired by him.”

Aware of the existence of online predators, she tries to limit the number of people who know the family’s home address. “We do get weird emails and DMs like ‘We will meet him no matter what you say,’” Ms. Jackson said.

In May, a video of him putting out the candle on a birthday cake by kicking a ball that hits and extinguishes the flame went viral. His parents sold the licensing rights to Jukin Media, and took him to the bank to open an account in his name, where any payment related to his videos would be deposited. He has earned about $5,000. “That’s Korbin’s money, not ours,” she said.