Banks earn a neat income by charging those clients who do not maintain minimum average balance and this is the income which helps them cover up their NPAs to a great extent as private banks charge a whopping Rs 750 per quarter for non maintenance of the balance. Have a look at the announcement ICICI bank has made as they have shifted from quarterly average balance to Monthly balance which means that they have a higher chance to catch the non maintenance culprits.
"Dear Customer, please be informed that with effect from April 1, 2012, the minimum average balance in your savings account will need to be maintained on monthly basis instead of quarterly. Charges for non-maintenance of minimum average balance will be applicable on a monthly basis thereof.”
Earlier one had a chance to recoup the balance in a quarter and now with a monthly balance, one has to be really careful.