I pay my Discover in full every month and always get cash back credit for the prior month charges.
IN FULL has been said lots here ...
Statement balance IN FULL ?
Every month for years. My Discover card is my checking account, and getting this cash back (I just apply it to the monthly bill) totals out to a hundred bucks or more every year. Only thing is using credit for gas has no advantage anymore since theres usually a 10 cent per gallon upcharge .