• by Sarah Mahoney  @mahoney_sarah, April 2, 2008

In an ongoing effort to convince shoppers that it's an earth-friendly store, Wal-Mart says it has unleashed its biggest green marketing effort yet.

And it's doing it with a wallet-friendly twist: Seven new TV spots extol the environmental virtues of products, while emphasizing how affordable they are. One ad, for example, focuses on a pair of teenagers in Coke-branded T-shirts, made from recycled Coke bottles, for under $7.50. Another features a woman bragging about the savings benefits of a GE CFL light bulb.

Calling it the company's "most comprehensive environmental sustainability campaign," the Bentonville, Ark.-based retailer says the ads will run throughout April, and that the point is to convince the millions of Wal-Mart shoppers they can effect environmental changes without blowing their budgets.

"Wal-Mart is uniquely positioned to make sustainable choices a real option for hundreds of millions of Americans--not just the few who until now could afford to choose them," the company says.

Wal-Mart is also expanding its efforts to educate consumers on relatively tricky nuances of manufacturing green products. For example, it's selling Faded Glory Transitional Cotton T-shirts for $3.50.

Transitional cotton, which means it cannot yet be certified as organic, typically can't command organic prices. Wal-Mart says it "helps these farmers by paying certified organic prices during the transition, without passing along increased cost to customers."

Another featured product is Majestic Rubber Mulch, made from 100% recycled tire rubber.

In addition to TV, the national campaign also includes print, radio and online ads as well as a 16-page insert in May magazines.