So if you have a credit card but never use it, you can increase your score by making occasional purchases and paying them off. (moneysense.ca)
But if there are smaller transactions built to entice frequent / occasional purchases forever... count me out. (gonintendo.com)
The cash rewards don't expire either, so you're also free to build up your rewards slowly if you prefer to only use your card for occasional purchases. (creditcards.com)