"Are you reading anything good?"
Most recently I asked this of a woman holding The Poisonwood Bible, which I adored.
"Yes!" she said, waving the book in front of me. "I'm almost done. This book has changed my life."
Hearing that a book changed someone's life is one of my greatest pleasures. I can't think of a better compliment an author could hear. Unfortunately, my follow-up question doesn't always yield a satisfying answer:
"How?" I said. Meaning, how did it change your life?
"Because it was amazing!" she said.
This is a pretty typical response, and I know I do it sometimes as well.
"Because it was just so good!"
"It was incredible!"
"I loved it!"
These are all great to hear, but none of them indicate any clues about how a life might have been changed, not that anyone owes me an explanation if I ask. Still, "This changed my life!" is pretty high praise and shouldn't be interchangeable with "This book is ...