Have you ever received a credit card that had a really low interest rate compare to those on one or more other cards?  

So naturally you wanted to transfer the balance from the high interest card to the low interest card.  BUT that low rate is only for purchases and/or there is a "balance transfer fee". 

There are likely things that you currently pay for with cash or maybe a check which you could use the lower rate card to pay for.  Now take the money that you would have paid for those items/services and send that to the higher rate card(s). 

Here's a quick example.  You owe Chase Bank $1000 on a card with a rate of 15%.  You received a card from Bank of America with a rate of 9%.

Your electric company might take Visa - pay them using the BofA card and send the money that you would have paid to the electric company to Chase.  Does the cable company take Visa?  Do the same there.  Keep going down the list of bills.  Now do this for a few months until the Chase card is paid off. 

You've effectively transfered the balance from the Chase card to the BofA card.