As you can see for almost all products there is a 0% EMI option open for the buyer so that he can buy it even if he doesn’t have the amount to pay. But if you look at it closely there will be a onetime charge (they call it processing charge or some other wordings) which is more than or equivalent to 12-13% of the total amount. In that way bank is getting the interest beforehand in a single installment. I think it is always better to pay it from your pocket or opt for COD (Cash on Delivery) and it will lessen the burden on your pocket. EMI option is just to tempt you to go for the product and at the same time the bank is benefiting out of it. If you fail to pay any installment penalty would be very high too.