J. Rogal

"People don't want to wait these days," says Kal Abhari, a storeowner in Arnold, Mo., near St. Louis. "It all comes down to customer service and speed."

Grocery shoppers in recent years have become accustomed to seeing and hearing coin-counting machines chugging away at the front of the store. But they might not know that Coinstar Inc., the largest owner of these counters, is not content with the easy money that comes from charging customers an 8.9% fee to change their coins into store vouchers or cash.