Plastic Jungle, a site where you can sell unwanted gift cards or buy those cards at a discount, has raised $7.4 million in a second round of funding.

I actually wrote about new site with a similar idea called CardPool just a few hours ago. Both CardPool and Plastic Jungle are part of a larger category of gift card marketplaces, which also includes Swapagift. One of Plastic Jungle’s more attractive features is the ability to not just sell a card for slightly less than the official dollar value, but also to receive a higher amount in the form of an Amazon gift card.

The Mountain View, Calif. company says that during the 2009-10 holiday season, it made 450 percent more revenue than during the same period in 2008-09. The site also reports that it saves $35 on average per buyer, and that sellers usually receive an average of $110 per card.

Plastic Jungle previously raised $6 million from Shasta Ventures, who also participated in the new funding. This round was led by Redpoint Ventures.