PMFJI but if the interest-free period were removed, seems to me the only reason to use a credit card would be for chargeback protection. That matters for risky purchases- e.g. buying an ipod on Ebay from somebody in South Carolina who says it is "mint" - but not for purchases from supermarkets, big brick-and-mortar stores or online retailers that have very good consumer policies anyway. The sorts of people who pay off their card every month might as well start paying via debit card or even cash to avoid the CC interest, additionally asking the retailer to pass on some of the CC fee that's been saved. So the CC issuers may end up with lots of smaller risky transactions while the low-risk big-ticket items all go elsewhere. They may end up wishing they'd let sleeping dogs lie. ;-)