Every once in a while, my credit card will have a "special limited-time offer" in the form of a additional statement credit on a specific purchase category.
For instance, the most recent one was a 2% statement credit on grocery and drugstore purchases for two months.
What's the point of these? I already get some rewards from this credit card, why do they want to give more rewards? Does the credit card company get anything from this?
Additionally, I am wondering why these offers always require me to do something to opt in (usually visit some website and enter a special code). Why make them explicitly opt-in instead of automatically enrolling everyone?