How much can you save? Wal-Mart not allowed to tell

The Better Business Bureau

has a beef with Wal-Mart's ad claims that it saves shoppers $700 a year.

It's been asked to stop running the ads and this little story (subscription required) found in the Wall Street Journal today is an opportunity to shine some light on how retailers assess and set prices, and how you can make sense of it all.

Retailers employ all manner of technology to set prices. They hire consultants, secretly shop the competition and use price optimization software to analyze and determine the correct cost of goods.

So when a company as huge and efficient as Wal-Mart makes a claim that shoppers can save up to $700 a year by shopping its stores, and then says that claim is supported by a study from another large International company, you'd think it would be pretty solid.