40 Year Mortgage Refinance

How do you make your mortgage payment every two weeks save you money?
I got a letter in the mail from the bank that says to pay our mortgage payment every two weeks instead of monthly could save us $ 40,000 to $ 100,000 in interest and reduce our mortgage term with 7-9 years without refinancing. How does it work?
The "interest in 15 days instead of 30" is not always the case. Many mortgage companies that offer this program only with the first half, until the second half coming. The mortgage company will make some interest, holding all those half payments for 15 days, but you do not. The real benefit is that each pay 2 weeks to do in 13 months. You're making an extra payment goes to principal. You do not have to pay the mortgage company $ 300 or $ 3,000 (regardless of the current fee) to set this up. You can pay extra on your principal when you wish. Even pay as little as $ 10 each month will shorten your loan.