It's the time of year when fundraising appeals are piling up in inboxes and mailboxes all over the country. But these days, certain appeals have a different tone.
Cheeky crowdfunding sites like crowdrise.com are mixing in humor with their pitches, aiming at "people in college or people who still want to be in college," according to Robert Wolfe, the CEO. (The taunt to visitors, that "if you don't give back, no one will like you," is a case in point.)
"We want to make giving back fun. We don't want to just be a tool," Wolfe said.
At the same time, charity gift catalogs are proliferating, offering donors the opportunity to "buy" everything from a goat to a sewing machine to a herd of cows.
The idea—that people will respond better if they have a concrete idea about where their donation is going—has caught fire in recent years. For example, World Vision, a Christian anti-poverty organization, brought in $25 million from its catalog in 2008, and increased that to $33 million in 2012, according to Cheryl deBruler, coordinator of the catalog's production.
"Over the years, the gift catalog has become more and more important," she said.
(Read more: World's most big–hearted nation: the United States)
Beyond the fun and the heartstring-tugging pictures, both types of fundraising also seem to offer greater directness. What could be more straightforward than buying a llama for that little girl with the radiant smile? Or sending money to the Cure JM Foundation when your friend asks you to help her meet an online matching gift challenge?
But look more closely at your gift catalog, or your crowdfunding site, and you'll see more.
For example, World Vision promises "to honor your generosity and use your donation in the most effective way possible." In other words, while the catalog may offer the option of donating a goat or several ducks, "donations will be used to provide assistance where it is needed most within that category or to address a similar need," World Vision says.
Similarly, when Heifer International, which brings sustainable agriculture and commerce to needy communities, was started by an Indiana farmer 70 years ago, he got fellow farmers to donate heifers, and then got the animals shipped to eastern Europe and elsewhere. Pierre Ferrari, the chief executive, says it's possible to trace the genes of heifers now living in Poland and Germany back to those original donations. Over time that practice became unwieldy, and now Heifer makes clear that "donations" of goats and other livestock are symbolic.
At Crowdrise, while the donating process seems completely streamlined, the company actually takes a 3 percent cut of every contribution made on the site. "Transaction Fees cover CrowdRise's costs associated with developing, maintaining and hosting the Site, plus other value-added services," the site says.
Before you check out of crowdfunding or charity gift catalogs, though, consider this: these fundraising vehicles are remarkably effective. Your gift may not follow the straight line you imagine, or reach a charity untouched, but it may well be money that the organization would not receive otherwise.
(Read more: Charities get holiday boost from crowdfunding)
Crowdrise is currently running a holiday challenge, in which a group of donors have pooled gifts totaling $200,000 for Crowdrise to allocate to the charities that raise the most money between Nov. 18 and Jan. 9. A charity's supporters then go out to their friends and ask for donations, competing for the challenge prizes. So far, the holiday challenge has raised over $668,000 for charities, more than five times the amount raised at this point in the 2012 holiday challenge, Wolfe said.
"If I want to raise $40,000, I'll send an email to 500,000 people hoping to get a 2 percent conversion—or I can go get 25 people to go raise $2,000 for me," he said. "If you can get 25 passionate people to go do that, it's so much more effective."
(Read more: It's the way you donate that counts)
Similarly, at Heifer, Ferrari said he believes the symbolic nature of donations is understood "among adults, yes, among children, no." But he argues that the general intent behind donors' gifts is honored.
"It's true that if you buy a goat, I can't guarantee that your $120 will go to somebody in Malawi. But I can guarantee that a goat will be placed," he said. The catalog also offers concrete explanations of how charity works, drawing in even young children, he said.
Heifer is also able to use gift catalog and other donations as leverage to obtain government funding for its projects.
"We are able to leverage our money with government sources, or the World Bank, or local governments, or communities, sometimes four to one," he said. And because Heifer requires gift recipients to pass on their good fortune, giving a baby goat or baby chicks to neighbors, the effect of every donated animal is multiplied.
World Vision's deBruler says her organization's catalog creates an incentive for donors to give repeatedly. "We're able to to set up traditions with families," she said. "Because these donors are considering giving for Christmas, the catalog has become part of their tradition."
What you give may not be exactly what your charity gets, but you're still giving plenty. And if you don't see a novel giving opportunity that excites you, just wait five minutes: New ones are always in the works.
—By CNBC's Kelley Holland. Follow her on Twitter @KKelleyHolland.