If you are applying for a new credit card then you have to understand that there are several costs from the credit card you are going to take. One of the important costs is the interest expenses of the credit card.

You need to know about the interest rate offered by the provider so you will be able to count the interest expenses you should pay. Banks generally borrow the money they then lend to their customers. As they receive very low-interest loans from other firms, they may borrow as much as their customers require, while lending their capital to other borrowers at higher rates.

If the card issuer charges 15% on money lent to users, and it costs 5% to borrow the money to lend, and the balance sits with the cardholder for a year, the issuer earns 10% on the loan. This 5% difference is the "interest expense" and the 10% is the "net interest spread". So, please ask the provider more about it.