Man's tweet about his father's empty doughnut shop has a sweet ending

A man in Missouri City, Texas, who just opened a doughnut shop got a sweet surprise, thanks to his son and the magic of social media.

On Saturday, Billy By posted a photo on Twitter, showing his father, Satharith By, in his empty bakery, Billy's Donuts.

The doughnut shop -- named after his son -- was Satharith By's American dream finally come true. Yet, despite the grand-opening sign outside the store, few customers were stopping by. So, Billy By took to Twitter.

"My dad is sad cause no one is coming to his new donut shop," Billy By tweeted.

Responses were immediate, and the post was retweeted about 306,000 times. When people said they wanted to come by and asked for more information, Billy By tweeted the address to his father's shop.

On Sunday, Billy By tweeted that the shop had sold out of food. He shared with ABC News images of customers lined up inside the shop prior to close.

"Just wanted to update yall! We completely sold out of donuts and kolaches! You are all amazing. I can't thank everyone enough for coming out and supporting local businesses. This means so much to my family," he tweeted.

Billy By told ABC News on Monday that he was incredibly grateful for everyone who shared his message and came by his father's store.

"I love Houston," he said. "I'll never leave the city!"