Clipping coupons has always been a way for shoppers to save a little money at the check-out line. Some people have turned couponing into full-time jobs, saving as much as 80 to 90% at the cash register. Such exploits have been documented on television, prompting many viewers to try to emulate that success. But such tactics may be at the expense of regular shoppers.

Here are some things extreme couponers have in common.

• They live in areas where the stores accept multiple coupons for one item.

• The stores at which they shop double all the coupons.

• They spend hours a week scouring for deals and matching up coupons to in-store sales.

• They purchase huge quantities of one particular item to stockpile.

Although there are many shoppers who have learned some tactics from watching extreme couponing shows or subscribing to coupon message boards and web sites, the influx of coupon use has caused a shift in the ways many stores are doing business.

Some changes are spurred partially by shady coupon tactics, including illegal duplicating and even stealing coupons from neighbors and stores. Another fraudulent couponing tactic that has been brought to light through some extreme couponers is the use of product family codes on coupons to purchase items with coupons for another product. In essence, because the UPC codes of some manufacturer items are similar on products within their family of items, it may be possible to pass off a coupon for one product, say refrigerated biscuits, when you’re actually purchasing refrigerated pizza crust because the barcode reader on the register doesn’t alert to an incorrect code. Newer barcodes are helping to correct this problem. Decoding UPC symbols and barcodes is not smart shopping, it’s illegal and it stands to hurt the consumers who use coupons in a legal way. Here’s how;

If the manufacturer who issued coupons wishes to audit the store for a particular transaction where coupon fraud seemed to be the case, and the manufacturer determines that the correct products were not purchased with these coupons, the manufacturer can refuse to reimburse the store for them. As a result, the store will have to absorb the cost of this shopping trip, because the terms of the coupon were not followed. Should that occur, the store can then mark up other items to offset the loss, which affects other shoppers. Or the store may rethink its policy on coupons.

Some grocery stores have revamped their policies on coupons. Price Chopper in St. Johnsbury, VT, recently ceased doubling coupons up to $1.00. Now they cap it at $.99. Kroger stores in Houston have also stopped doubling or tripling coupons as of April 2011. Stores like Kroger have stated that since the stores -- and not the product manufacturers -- absorb the cost of doubling and tripling coupons, many can no longer afford to do so.

Many stores do not allow the use of multiple coupons for one item as well, which is a rarity at some stores. That means a person will have to have one coupon per each item to realize a discount.

Coupons remain a way to save money when used in the correct way. There are web sites that will publish store sales and match coupons to those sales so shoppers can shop smartly. By shopping legally, coupons continue to benefit many communities.

Courtesy MS