There's no such thing as a free lunch. All credit cards come with associated costs when used to make purchases, even if it’s simply the cost of making repayments.
However, many lenders offer incentives for customers such as a $0 annual fee or 0 per cent interest on purchases during an introductory period. Additionally, paying off your balance in full during an interest-free period means you could only have to pay back the cost of purchases without interest. You could also be eligible for additional rewards such as cashback during that time, saving you more money.