Since its launch a few years ago, eBay's eco-store has been working both angles of the word "green," helping people make money by reselling old stuff and retailing new eco-friendly products. In honor of the Earth Day's 40th, the retail giant is offering a Green Team challenge.

If you sign up between now and Earth Day, eBay will offer to protect an acre of lush, green rain forest in the Congo, Brazil or Mexico and it will enter you to win the other kind of green — 10K. 

If you are a regular eBay user, you won't have to do much other than log in and join the Green Team, but if you haven't logged on in a while ... good luck! It took me about 37 tries and multiple verifications before I could log on. But then the rest is easy ... hardly a challenge at all. No specific actions or pledges are required (just the usual green tips offered), and of course there is a pointer to the eBay Green store.

But who's complaining? A shot at saving a rain forest and winning money doesn't come along that often, so take it!

eBay Green's Earth Day sweepstakes
Take eBay's Green Team challenge, and the company will protect an acre of rain forest and enter you to win $10,000.