Will a credit card issuer cancel an account if it never incurs interest?
Speaking from personal experience: I have had a credit card canceled for exactly this reason. It's happened to me three times, with two different providers (NatWest and Nationwide). After the third instance I stopped bothering to even carry a credit card. It's worth noting that all three were "free" cards in the sense that I paid no flat fee or subscription to get the cards. The only way the issuer could make a profit on them was through interest. I was also not a frequent user, carrying the card for convenience more than anything else, although I did make purchases on all three. So it's certainly a possibility. But I live in the UK and I'm guessing most of your other respondents do not. It may be a practice that's more common here than in the US. That might even explain the origin of the rumour.