By Guest Blogger Donna DeClemente, Donna's Promo Talk

Last month Walmart kicked off a new "Green" promotional marketing campaign with its first #WinItWednesday contest on Twitter. The contest gives entrants the chance to share their unique eco-friendly ideas and to win Walmart Gift Cards. The contest takes place on the first Wednesday of each month, so today is round two for the month of March.

Today @WalmartGreen will ask Twitter users to respond to a specific #WinItWednesday sustainability inspired challenge question. Three winners will be selected by judges representing Wal-Mart Stores, and the Mother Nature Network for each month's challenge question. Participants must follow and reply to @WalmartGreen and include the hashtag #WinItWednesday in their tweet. Each of the three winners will receive a $100 Walmart gift card and a chance to have their Submission featured on Mother Nature Network’s The Leaderboard and The Green Room, Walmart's sustainability blog, within that month.

For the first contest entrants were invited to share their idea for an eco-friendly gift for their Valentine (in 140 characters or less !). This first contest resulted in a 5.4% spike for @WalmartGreen in their number of Twitter followers in only 6 hours. This equaled 1.5 new followers every minute. The contest was also mentioned by John McCain and Planet Green on Twitter! Here's an overview of last month's winners which includes Terri Pointon who's idea is turning old wool and cashmere sweaters into new items.

Walmart's “The Leaderboard” was launched earlier this year through a new partnership formed with the Mother Nature Network with the purpose of creating a special editorial channel on the site for readers to explore the people, businesses and organizations leading in sustainability.

“Thanks to the ingenuity, passion and innovative thinking of so many people, we’ve seen an increase in sustainable technologies, processes and options in the past decade,” said Andrea Thomas, senior vice president of sustainability at Walmart. “These new ideas have helped companies, like Walmart, make significant progress toward our sustainability goals. Walmart has a responsibility to use its size and scale to influence positive change, and we believe ‘The Leaderboard’ will be a place to showcase cutting edge ideas and spark further adoption.”

Today's challenge question is scheduled to be posted at 11am ET, so check it out and share a tweet @WalMart Green with one of your eco-friendly ideas.