Sometimes if you have to pay only the interest for using credit card to make a purchase of bitcoins can be profitable if there are no hidden charges as credit cards will charge you a fixed amount of interest which you can easily cover by trading with those bitcoins in a certain amount of time.

You have to be a pro-trader actually to cover up that amount of interest and start having you own profits on it. Credit card purchases can be beneficial as they might charge you on a yearly basis and might be their interest rate varies from 10% to 30% which is not that excess and we could manage to earn that amount of interest in 2 to 3 months of time so we can easily pay off that debts and for the rest of the months we could have profits for ourselves.