Hundreds of people are taking selfies and posting them on social media under the hashtags #givingTuesday and #unselfie to show their involvement in charitable causes.
According to the Unselfie campaign, launched by NGO Central New York Community Foundation (CNYCF), participants have to take pictures of themselves holding a piece of paper describing their acts of kindness.
The movement is taking place on Tuesday (2 December) along with Giving Tuesday, an initiative aimed at helping needy people, occurring two days after Black Friday, when hundreds of thousands of people go on a shopping spree to make the most of bargain deals.
According to Monica Priest, program manager at NGO Volunteer Kalamazoo and one of Giving Tuesday's coordinators, the day is an occasion to be unselfish and it offers dozens of opportunities to volunteer.
"When people tell me they don't have time to volunteer, I tell them if you just make 10, 15, 20 minutes out of your day just to go do something nice, it may not seem like it has much of an effect, but it truly does in the lives of the people that you touch.
"Even if it's just a one-time volunteering activity on Giving Tuesday, I guarantee you'll have such a great time, you'll want to do it again!"
Peter Dunn, president and CEO of CNYCF, said: "Giving Tuesday is an effort launched a couple years ago to focus people around the country away from the consumer aspects of the holiday season and toward the concept of charitable giving as part of the holiday season."