Cash Back vs Miles

Q. I’m using up my frequent flier miles as fast as I can because they're getting impossible to use, plus they keep on adding fees and increasing the miles required for a “free” ticket. So I'm going to get rid of my airline credit cards and switch to “cash back” card. Which one do you recommend?

A. We like the Blue Cash Card from American Express, which gives you unlimited 5% cash back on purchases made at gas stations, grocery stores, and drug stores and 1.25% on everything else, once your spending reaches $6500.