Wal-Mart stores, Supercenters and Sam's Clubs across Minnesota will host a fluorescent light bulb recycling day Saturday, a first-time move experts expect will help the retailer cultivate an environmentally friendly image and perhaps drive sales.

"The secret to retailing is, 'How do you drive footsteps?' said Howard Davidowitz, chairman of Davidowitz & Associates Inc., a retail consulting and investment banking firm in New York. "Any time you drive people into your stores, you win."

Retailing giant Wal-Mart, under fire from activist groups for its labor practices and from Wall Street of late for sluggish sales growth, has been pursuing an aggressive environmental campaign. The aim is both to improve efficiency of the company's operations as well as to boost sales in stores. "We've been looking for several different ways to be responsible stewards for our environment," said Julie Idelkope, a spokeswoman.

Replacing a conventional light bulb with a compact fluorescent light bulb (CFLs) can over the lifetime of the bulb save up to $30 in electricity costs, prevent more than 110 pounds of coal from being burned, and reduce greenhouse gas emissions by 450 pounds. However, the light bulbs should be recycled because they contain a small amount of mercury.

Other retailers have been making similar efforts "but no one as boldly and consistently" as Wal-Mart in the last year, said Joel Makower, executive editor of greenbiz.com.

"This