Suitable for casual conversations and not for formal settings like business meetings. She's mad for Broadway shows — already seen the same one five times!
Pro Tip 2/3
Intensity
Expresses a very strong level of enthusiasm, going beyond just liking something. I'm mad for vintage cars; I even fly to exhibitions.
Pro Tip 3/3
Not Literal
It's a figurative expression and doesn't mean being angry or mentally unstable. He's mad for chess, but he's the calmest person I know.