The days following Thanksgiving have been all about buy, buy, buy. But amid the discounts and sales, charities are trumpeting another mantra: Give, give, give.

Tomorrow is Giving Tuesday, an annual national day of giving that aims to be the Black Friday or Cyber Monday of philanthropy. Nearly 7,000 nonprofits, philanthropic groups and businesses have unleashed social media campaigns encouraging people to go online and give to various causes.

On last year’s Giving Tuesday, online giving doubled nationally, and PayPal mobile donations soared 487 percent, compared with the same day the previous year.

Local officials around the country have endorsed the event; Baltimore Mayor Stephanie Rawlings-Blake, for instance, set a goal for the city to raise at least $5 million on Tuesday. Giving Tuesday campaigns have even popped up in countries such as Canada, Chile, the United Kingdom, Mexico and Singapore.

“There’s clearly an appetite for people to talk about ways they want to give,” said Aaron Sherinian, a vice president at the United Nations Foundation, one of the groups that founded the event. “They want to use not just their wallet but their voice and social media profiles to talk about where they give their time and money.”

Similar to other daylong campaigns such as Give to the Max and Do More 24, charity groups are more eager to increase the number of donors rather than the amount of donations.

Theater company Woolly Mammoth of the District raised $10,815 from 49 donors last year. The total was a fraction of its $4.5 million annual budget, but officials say it helps tap an important revenue stream.

“In these times, you can’t count on one revenue stream over the other,” said Sarah S. Dovere, Woolly Mammoth’s director of development. “Every gift that we receive no matter how large or small it truly does make a difference.”

This year the group hopes to secure 75 new donors. It has already deployed a group of volunteers and supporters to ask family, friends and colleagues for donations on Giving Tuesday.

That potential to reach new donors is why the Boys and Girls Club of Greater Washington jumped on board this year. The group hopes to raise $1,500 on the day by creating a social media campaign and organizing a fundraising event.

“It didn’t make sense not to leverage this day,” said Ebonie Johnson Cooper, director of marketing and communication for the Boys and Girls Clubs of Greater Washington. “It really creates a sense of community online.”

The following is a sample of what some nonprofits and businesses, locally and elsewhere, are doing to prepare for a possible fundraising harvest.

Asian Development Bank’s North America regional office is donating 200 sandwiches to Martha’s Table and continues the service each month.

Benevolent Media of the District is hosting a marketplace of environmentally friendly art and crafts. The media and events company plans to include family-friendly activities featuring local artists, businesses and nonprofits.

The Case Foundation is teaming up with Crowdrise, Network for Good and Six Degrees to host an online page where donors can support featured nonprofits and have their contributions matched.

The Congressional Black Caucus Foundation of the District is using its Giving Tuesday event to honor its 2013 interns.

Crowdvance, a District fundraising platform for small organizations, is encouraging donors to give $5 or more to charities and get free gift cards for sites including, and Movie

Darlington House, a Dupont Circle restaurant, is giving 20 percent of its proceeds to the Mastocytosis Society.

Discover is providing a 2 percent match to designated charitable partners when card holders make a donation to them.

Dolci Gelati, a District artisan gelato company, is giving 20 percent of the sales from its Takoma Park location to the Millennial Action Project, an organization that helps foster political collaboration among millennials.

Georgetown University is encouraging alumni and supporters to share philanthropy stories on a Web site they created for Giving Tuesday.

Hewlett-Packard’s D.C. office is using its Political Action Committee to offer a one-to-one match to charitable organizations.

The Latin American Youth Center of the District is hosting an open house at its Columbia Heights site, where it plans to kick off its coat drive with holiday music, refreshments and games.

The Many Hats Institute, a youth development nonprofit based in the District, is hosting a fundraising happy hour called “Sports 4 Inspiration” to benefit the Boys and Girls Club of Greater Washington.

Microsoft is launching a campaign to raise $500,000 for Give for Youth to create education, employment and entrepreneurship opportunities for young people.

Razoo, a District based crowdfunding site for causes, is awarding $100,000 in donations to nonprofits that use the site for GivingTuesday fundraising.

St. Regis Washington D.C. is hosting a fundraiser with a handful of other small businesses to support Creative Minds International Public Charter School. Miss America DC is scheduled to make an appearance.

TinyGive, a District-based company that uses tweets to raise money for charities, is giving away $12,000 in matching funds to selected nonprofits.

Truist, a District based online corporate philanthropy platform, is creating a Web site specifically for Giving Tuesday.

The Trust for the National Mall is creating the Stories of Success campaign which will share how donations have impacted projects on the National Mall.

Unilever is holding an employee food drive.

The United Way is encouraging people to become mentors and tutors in their communities.

Volunteers of America Chesapeake, a health and human services nonprofit, has teamed up with OneCause on Cyber Monday to give consumers a portal to shop online at their favorite retailers with a percentage of their purchase contributing to the cause of their choice. For Giving Tuesday the charity created a Web page for donors to give to specific projects.