We all hear that in order to capture our readers' interest, we have to make them care about our main character on the first page. But caring is a very subjective concept. We all have different ways of connecting. A detail that grabs one person's attention may be completely meaningless to someone else.
It seems that gender is a factor, too. Women seem to need more of an emotional connection, while men might be drawn into an exciting situation without knowing anything about the characters.
One of my pet peeves as a reader is the assumption that just because someone is in danger, I care about them. I don't. For all I know, they deserve to be in danger. Perhaps that woman being stalked in the parking garage at night is just too stupid to live. Perhaps she's actually the villain and her victim is seeking revenge.
Even if neither of those premises is true, I still need to care about her somehow.
What do you think is the key to making readers care?