Serious couponers have been spoiled for years by Cub Foods expired coupon policy. The SuperValu stores have accepted coupons up to 90 days past the expiration date. Some cashiers even stretched it to five or six months, according to the Pocket Your Dollars couponing website.

But starting April 15, Cub will only accept coupons up to 30 days past the expiration date, said Cub Foods spokesman Luke Friedrich. "It brings us more closely aligned with manufacturer expectations," he said, explaining the reason for the change.

The fact that Cub is the only supermarket in the TWin Cities that accepts expired manufacturer coupons has always been a mystery. Retailers are not supposed to accept expired coupons, according to the coupon's terms of compliance, said Charlie Brown of NCH Marketing, an Illinois coupon clearinghouse, There is a time lag between the time of redemption and the time when the coupon gets to clearinghouses, which allows Cub to do it. Apparently, enforcement is not a high priority.

No doubt Cub wants to maintain the advantage that acceptance of expired coupons gives the supermarket. It's competing with Rainbow's double coupon days on Wednesdays and occasionally on Saturdays. But the real competition which makes groceries such a cutthroat business now is discounters such as Target, Wal-Mart, Trader Joe's and Aldi.

It's a tough business, but Cub Foods has been the long-time dominant retailer in the Twin Cities for many years, said John Dean, a Twin Cities supermarket analyst. "They're still the dominant retailer by a long shot," said Dean, but their market share has slipped from 37 percent in 2007 to 29 percent this year.

Will Cub's revised coupon policy affect where you spend your grocery dollars?