When you go to a store, how closely do you watch when your purchases are rung up?

The scanning machines are basically scammers. We have too much faith in computers. If you're not watching carefully, you may overpay.

Massachusetts monitors retailer pricing more closely than almost any other state. They even issue fines to retailers that overcharge. The Boston Globe now reports that the CVS drugstore chain had a 67% increase of overcharging in the state during 2008. By comparison, arch rival Walgreen's had virtually no instances of overcharging.

The article quotes a longtime CVS insider who argues the company believes it's cheaper to pay the fines than to give people the right price. But in Clark's book, that really undermines a brand's credibility.

So don't trust the register scanners. Watch your items as they're rung up. And you definitely don't want to be distracted by talking on your cell at the register.

Meanwhile, Newsday reports that Best Buy is facing a class-action lawsuit over its "meet or beat" price policy.

Best Buy's price-protection policy applies to competitors in the local market area -- but "market area" is not defined. That's allowed the electronics retailer to deny customer requests for cheaper prices and prompted the lawsuit.