I use plastic everywhere. My 5% cash back card just sent me a cancellation notice. It read something to the effect "due to business reasons, we have decided to close your account". Interesting timing, they just mailed me a $500 cash back check. I'll get them for another couple hundred this month.
But the way I read it is... "since inception of our credit relationship, where we entice you into accepting all of our too good to be true offers, and then crouch and wait for you to violate one of our hidden technicalities so we can bury you in fees and pentaties to help us pay for all we 'give' you, we have found that your account is paid off monthly and is only costing us money. We can no longer operate this way"
But if I did have accounts, they'd be at electrical suppliers and then wholesalers like Grainger.