All the attention may be on the fact that the internet is coming to dominate more and more of the holiday shopping market, but the internet seems to also be the place where many people will unload their unwanted gifts. Internet Retailer reports that while 64 percent of people surveyed "re-gift" items to other people in a giving chain of misfortune, one in five has actually sold a gift for cash. eBay is promoting itself as the go-to location for such furtive sales. Other companies are hoping to make some money around the margins as well. Cardavenue.com, for instance, allows users to swap gift certificate cards, taking a 6.25 percent cut of the value via PayPal.