At the supermarket checkout stand, Laurie Arndt heard the man behind her say with surprise, “She got all those bags of groceries for $40.”

Arndt got all those bags of groceries for $40 because she clips coupons. An Edgewood, Wash., mother of seven, she snips coupons from the pages of her newspaper.

“We usually save $20 to $30 a week,” she said. “I regularly plan my menus around the coupons. If tomatoes are on sale, I’ll make salsa, and we’ll have tacos this week.”

She typically uses coupons for such basics as produce, butter, milk and eggs. She knows of a supermarket chain that honors coupons printed by other stores, so that’s where she shops.

Within reason.

“I could use Costco coupons at Albertsons, but I don’t think it’s fair,” she said.

She does enjoy saving the money. “I’m kind of elated sometimes,” she said.

She’s not alone. Americans last year saved an estimated $3 billion by clipping some 3.8 billion coupons, according to Stacie McAnuff, a member of the Promotion Marketing Association Coupon Council.

“Seventy-nine percent of people in the U.S. use coupons each year,” she said.

They use coupons without much difference in such demographic groups as age or income, although shoppers in suburbs and small towns are more likely to take the advantage than big-city dwellers. And the Midwest outshines either coast, McAnuff said.

She and the council believe both shoppers and stores come out on top:

Coupons benefit consumers.

“By spending 20 minutes a week, the average consumer can save up to 20 percent on grocery bills,” she said.

Companies issuing coupons benefit, too.

“One advantage to retailers is being able to measure return on investment, the value of the promotion dollar,” she said. “Coupons are very measurable.”

Along with her work with the council, McAnuff is employed by the marketing company Valassis, of Livonia, Mich. One of the company’s products is the “free-standing insert,” or FSI — special newspaper inserts that bear all those colorful coupons. Those inserts generate a lot of statistics:

l Fifty-eight million households receive at least one FSI. All major American newspapers offer an FSI.

l The average face value of a coupon increased by 4 cents to 89 cents in 2002, according to Promo Magazine.

l The top five retail redeemers of coupons are Kroger, Wal-Mart, Ahold (a Dutch chain operating several store brands), military commissaries and Safeway, Promo said.

Most coupons will never see the inside of a cash register. Those 3.8 billion coupons redeemed in 2002 represented only 1.46 percent of the total number of coupons distributed.

The United States is the leader in coupon use. In fact, we’re nearly alone. Until recently, McAnuff said, coupons were illegal in Germany.

McAnuff highlighted some tie-in trends in the coupon industry:

l Coupons have tie-ins with store club cards. “We’re looking at how to use frequent-shopper card data. Privacy is the biggest concern,” she said. Companies and brands “certainly don’t want to upset their customers.”

l Coupons are tied to product samples.

l Coupons also have tie-ins to public events.

l Coupons are being issued for big-ticket products such as furniture, electronics and automobiles.

l Internet coupons are available.

The idea of Internet coupons, McAnuff said, “is slow to catch on, but it’s viable. That’s something people may look at as demographics change. If you’re trying to get a younger market, that might be the way to go.”

For Laurie Arndt, the mother of seven, those coupons in the newspaper still work just fine. “It’s fun to save that much money,” she said.