Walmart's been a leader with this. It started with pasta several years ago when they quietly replace the long-time standard 16-oz box with a 12-oz box. Same box size, same price, less contents. Then they did it with sugar by replacing the standard five pound bag with a four pound, but so many people buy sugar that this was quickly caught and they had to go back to the five pound bag or lose sales.
Another scam to watch out for is electronics pricing. They'll take say a TV that Target, Best Buy, Circuit City, hh Gregg, etc., is selling for $500 and offer it for $349. They don't do this to sell the TV at $349. They do it because people see that TV, and that it's much cheaper than they've seen anywhere else, and assume that all the rest of the TVs in electronics are much cheaper too when in reality they've been priced higher than everyone else. The customers' reasoning is since they were looking to spend $500 anyway, why not spend a little more and get a better TV than they could get elsewhere for less money, which is a false belief. So they end up paying more for a bigger/better TV at Walmart than they would anywhere else. They started doing this with microwave ovens a decade ago and it works very well.
