Get Rich From People's Weakness

One of best ways to make a lot of money in America is to find a weakness in the average person's habits and charge them for it.  The financial service industry is a master at this game.  They are trying to win the interest game and you are the opponent.

Bank Fees

Banks made 37.8 billion dollars last year off of service charge fees.  They know that a fair percentage of people do not manage their accounts well and they can make money without providing much of a service. 

Since the balance shown on your ATM receipt does not generally reflect several of the last five days worth of purchases, it can be off by $500 to $1000 dollars.  If you forget (or your spouse did not know) that you wrote a house or car payment check three days ago, you may have several hundred dollars less than you think.

A good way to avoid this is to keep $1000 minimum in your checking account.  Basically you treat your account like $1000 means you have nothing to left to spend (at least not anything costing hundreds of dollars).  This $1000 serves as a short term emergency fund. 

Zero Down With No Interest For One Year

This ploy comes with fine print which allows the lender to charge extremely high interest rates going all

the way back to the day you purchased something if you ever make one late payment.  Of course, they know that a fair percentage of people will miss a payment.  That $2000 couch makes the lender over $4000.

The way to avoid this ploy is to buy everything in cash.  You are guaranteed not to lose the interest game if you don't borrow money.  Yes, this includes cars.  You can get a good car for $6000.   

Cash Your Pay Check Before You Get It

Payday lending services make interest rates of up to 400 percent from this weakness (400 is not a typo).  It is very much like "legal loan-sharking" only the loan sharks are actually cheaper according to this CNN money article. 

In this case, they prey on people who are in a financial bind and this "service" obviously makes the situation worse.  Therefore, never use a payday lending "service". You are better off not paying the least important bill and working it out with the lender or collection agency (as painful as that is).

Summary

The way to avoid these and various other schemes, is to not be financially weak.  Find ways to make interest (ethically) through investing rather than pay interest through borrowing or paying fees.