Technically, I didn't invoke the Nancy Pearl 50-page rule so much as drop the book in disgust.
I was told that this book had a kickass heroine (by my mother, I think), so I picked it up. I think I lasted about twenty pages. I was following the plot just fine, and then Friday gets raped. And she's slightly annoyed by it.
If this is a casual enough occurrence in this world that it warrants mild offense, it's not a world I want to spend any time in, thanks.