First came Black Friday. Then Cyber Monday. Now, “Giving Tuesday” is working to build a national day to tap some of the $600 billion Americans spend over the holidays.

Started in 2012 in New York, Giving Tuesday — the Tuesday after Thanksgiving — boasts heavyweight backers such as the United Nations Foundation, Microsoft and Skype. But a new study has found that only 18 percent of consumers know about it, showing the challenges of swiftly organizing a national movement — even one inspired by Minnesota’s Give to the Max Day.

Organizers, who say they were spurred by the 24-hour giving blitzes taking hold in some cities, said they never expected overnight success.

“We have this big long weekend all about spending … and we wanted to frame this as the opening day of the giving season, said Henry Timms, executive director of the 92nd Street Y in New York, a co-founder of Giving Tuesday. “We think 18 percent is a pretty good figure” for the fourth year.

Minnesota nonprofit leaders are watching with interest to see if a national giving movement can be as effective as one spearheaded by local nonprofits.

“The challenge is so much philanthropy is place-based,” said Jeremy Wells, a vice president at Minnesota Philanthropy Partners, a network of foundations in St. Paul. “I give to my church, my alma mater. … To have some kind of universal thing — without the full buy-in of your nonprofits — is extremely hard.”

Minnesota is no stranger to building a giving tradition. In 2008, a major foundation and key nonprofits launched Give to the Max Day, one of about a dozen such days nationally. It sparked donor e-mail blitzes and goofy charity fundraisers, and this year it pulled in $18 million in 24 hours for 5,000 nonprofits.

Giving Tuesday has sparked some creative fundraising, too. A group of St. Louis dads is organizing a diaper drive for the needy. A Chicago senior housing nonprofit is holding a slumber party. Some gamers have launched a “Gaming Tuesday” to raise money for children, said Giving Tuesday organizers.

There’s also corporate buy-in. PayPal is offering a 1 percent match on donations made on its platform. MSNBC will broadcast stories about the groups and charities participating. Microsoft will promote giving in its stores. The Smithsonian National Museum of American History is holding its first annual philanthropy symposium to coincide with the event.

Giving Tuesday also has activities in a dozen other countries, organizers said.

But with all that, it raised $48 million last year — up from $28 million the previous year. Depending on who you talk to, it’s impressive growth — or a sign that the model could use some tweaking.

Timms said the one-day dollar figures don’t reveal the full impact. Giving Tuesday also encourages volunteerism, and it kicks off a month of ­holiday giving.

Besides, he said, “We just got started.”

Needs name recognition

While 93 percent of consumers know about Black Friday, only 18 percent are familiar with Giving Tuesday, according to a study released last week by the John Templeton Foundation.

That may be particularly true in Minnesota, where Giving Tuesday is in its infancy.

While some Minnesota nonprofits are mentioning Giving Tuesday on their websites and Facebook pages, few are building fundraisers or events around it.

Jon Pratt, executive director of the Minnesota Council of Nonprofits, said he doesn’t know of any major campaigns taking place Tuesday.

“Maybe Give to the Max Day is using that oxygen here, so you don’t hear about it,” he said.

Lutheran Social Service of Minnesota, for example, is among the charities focusing fundraising on Give to the Max Day and its year-end ­campaign.

“The two communitywide giving days are so close together and similar in nature,” said Jackie Nelson, a spokeswoman for Lutheran Social Service. “It makes sense to focus time and energy on one.”

Take an ‘unselfie’

The Salvation Army of Minnesota and North Dakota, however, is launching its “Give Christmas Away” campaign on Tuesday, raising money to buy Christmas presents for those in need. It also is encouraging people to take an “unselfie” on Tuesday — a photo of themselves doing charitable work.

“We felt that people are starting to recognize it,” said Annette Bauer, Salvation Army spokeswoman. “We watch social media chatter and didn’t hear much before. Now it’s starting to take off.”

That would be welcome news to philanthropy leaders, who say different donors respond differently to appeals.

“Philanthropy as a percent of GDP in our country hasn’t grown in 50 years,” said Wells, noting that it’s hovered at roughly 2 percent. “We need to continue to think of more ways to get more people into the game. I think Giving Tuesday could be a ramp for some people.”