You can easily avoid these tricks…

Offers that promise 0% financing and free shipping are very attractive. But are you really getting a good deal?

Many consumers believe the numerical data they see and hear in advertisements. They are unlikely to check the math themselves or challenge the context of the numbers — so advertisers get away with enticing, deceptive claims.

Some actual sales pitches I’ve come across recently — and how to make smarter buying decisions…

BANKS

PITCH: “Earn six times the national average interest rate when you open a money-market account online with our bank.”

The bank can make such an impressive claim only because it is comparing its rate to the average rate that banks pay on regular savings accounts, not on competing money-market accounts.

Self-defense: Ask questions about an offer until you are comfortable that you have the information needed to make a direct, relevant comparison — so that you are comparing apples to apples. And even then, don’t be misled into comparing a specific offer to the “average” offer — after all, you want to know about the best offers around, not the average ones.

ONLINE/CATALOG RETAILERS

PITCH: “Add just $7 to your order to qualify for free shipping.”

Marketers know that the word “free” provides a big emotional charge — so much so that we perceive what’s being offered as significantly more valuable than it is.

Example: You order a shirt from a mail-order catalog over the phone for $23 plus $4.99 shipping. To qualify for free shipping, you would have to spend $7 more — so you wind up buying a T-shirt or some other product that you don’t need.

Self-defense: Buy what you reasonably can use at the price you want. If you get a freebie, that’s gravy.

PITCH: “This bed sells for 50% off the manufacturer’s suggested retail price.”

The manufacturer’s suggested retail price (MSRP) is a clever sales tool that’s routinely used to promote luxury goods and many other kinds of merchandise.

Letting you know the MSRP establishes what’s known as a “price anchor” in your mind. Because the actual price seems like a bargain relative to the MSRP, you’re more likely to buy — and less likely to try to negotiate.

Self-defense: Ignore MSRPs. They are purposely inflated figures that have little connection with the going market value of the item you are shopping for.

Better: Research how much competitors are selling identical and similar items for, and use this information as your price anchor in purchase negotiations. Many stores are prepared to match or beat competitors’ prices.

Exception: Some brands of luxury goods, such as high-end appliances, are sold at the MSRP because manufacturers threaten to cut retailers off if they sell the goods for less. But even in such cases, you can often get an effective discount by negotiating for related concessions — for example, having accessories, delivery or other items “thrown in.”

CAR DEALERSHIPS

PITCH: “0% financing or instant cash rebate on all 2011 vehicles.”

Many consumers opt for 0% financing because it sounds like a big money-saver. In fact, it is often not the best way to go.

Example: Say a new car is priced at $16,000. If you get financing elsewhere and pay the dealer in cash, you get an instant $3,000 rebate. If you finance with the dealership, you pay $16,000 but incur no finance charges for three years. In each case, the dealership’s goal is to sell you the car for $13,000. Zero-percent financing just means you’re prepaying the finance charges by agreeing to the higher price.

Self-defense: Focus on the total net cost of the car (or any other type of item on which you can choose financing or cash back). One major drawback to the 0% financing is that if you decide to pay off your loan early, you will not receive the rebate. Effectively you are agreeing to pay the entire finance charge no matter what happens in the future.