Giving portals like Createhope.org, iGive.com, and Charitableway.com list a variety of charities and accept money on their behalf. In return, they deduct a handling fee and pass the remainder of the donation on to a designated charity.

Michael Nilsen of the National Society of Fund Raising Executives told ABC News that these sites operate with a different mindset from most charities because they are businesses first and foremost.

"There's a bottom line," Nilsen said. "While they are certainly useful in raising awareness of philanthropy and acting as a conduit for donations … they need to make money."

Some for-profit portals take commissions as high as 15 percent off every contribution. Most deduct a service fee of about $5 per contribution, depending on the size of the gift.

Thegivingnetwork.com withholds 8 percent of donations and Helping.com deducts about 3 percent of the gift.

Many sites list charities and ministries among their sharing clientele without permission. Organizations like the American Lung Association (ala) now receive so many small contribution checks from various sites that they find it impossible to monitor the actual amount of money flowing in through indirect giving. The amount of money passed on to the ALA is "so minimal that we don't even track it," CEO Joseph Bergen told The Chronicle of Higher Education.

Stan Goude of the Salvation Army told ...