When a happy customer's letter of appreciation to the seller of a VHS machine was shared on social media, it prompted a stream of stories about acts of kindness.
"It caught my eye because most mail I get is either an advertisement or a bill, but this was handwritten," Matt Shoukry told the BBC.
"I was blown away by how much emotion and feeling this gentleman had put into a note, and how I felt so connected to him," Matt, from St Louis, Missouri, said.
Sweet and unexpected
"It was so unexpected but so sweet, so I decided to share it with the world on Reddit," Matt told the BBC. "There is so much negative in the world today, it's refreshing to have something wholesome and positive to share with everyone."
Matt's post was upvoted 160,000 times in just one day, with many people saying they were crying with emotion.
The letter from an 86-year-old man from Phoenix, Arizona, described how he had been watching tapes from his wedding, attended by family and friends, many of whom he said were no longer around.
He went on to say each of his tapes was more fun than the last and he liked watching the "gentle maturing" of his family.
Matt, who sells professionally online while recovering from cancer, has offered to digitize the gentleman's old tapes for him, "so he won't have to worry about them degrading and those memories will be preserved for future generations."
He also plans to frame the letter, which has since been shared on Twitter, garnering more than 300,000 likes and 58,000 retweets in two days.
Since then, people have been sharing their own tales of happiness and kindness.
Kindness costs nothing
Son bought rucksack from ebay, came with a lovely letter wishing him well in his future expeditions and detailing where it had travelled already!— guernseylib (@guernseylibrary) February 18, 2019
Kate Garnett bought her son a second-hand rucksack online when he was 16, ahead of a British expedition to Manu National Park in Peruvian Amazon.
When she told the seller about her son's plans and passion for plants, he said he would add a mosquito net, a bivvy bag (personal-sized waterproof shelter) and a torch free of charge, as his own expedition days were behind him.
"He liked the fact it was going to a good home and more adventure," Kate said. "It arrived with a letter saying where it had been: Europe, Asia, Australia and North America, but not South America," she told the BBC.
"Kindness costs nothing and the world needs it right now," Kate said.
Like, I showed an older woman how to Skype with her family in Japan and she tried to pay me. It melted my heart— Jim 👎 (@jtp2106) February 18, 2019
Jim in Brooklyn described how it "melted his heart" when a woman tried to pay him after he explained how she could Skype her family in Japan.
The two of them struck up a friendship whilst Jim was volunteering for a programme in New York, teaching older people computer basics, he told the BBC.
"She was really smart and eager to learn," he said. "I taught her how to use a Roku box (digital receiver), and introduced her to a language-learning app."
He added that volunteering with the older generation is "one of the most beautiful things I've ever done."
Friends to this day
Damien sold two action figures to a mother online, but her message back inspired him to send her all 30 of them...
I put some action figures on eBay, a mom bought 2 but not the other 28 I had. She mssged to say her autistic son was excited to get them. She wished she could have bought more. I sent her all 30 of them, got a phone call, she thanked me and cried. We’re all friends to this day.— Damien 🦇 (@DFacobbre) February 17, 2019