Question: Someone who read my manuscript told me they "didn't care" about my characters. What is this? A popularity contest? I don't want them to fall in love with my characters, only to keep on turning pages.
Answer: I'd pay close attention to motivation here.
Once an editor told me my manuscript "lacked tension" and I had no idea what she meant by that. Now I know it's because the reader didn't care enough about what happened to the characters. A reader should be invested in your story, should care about your characters and whether they get what they want, and eagerly turn the pages to find out what happens next.
One way to write page-turner fiction is to build tension and suspense into every scene..
Without those two elements, there is no real story. Someone has to want
something – usually, it’s the main character – and wondering whether
they will get it or not is the definition of reader suspense. For tension to be
present, the reader has to care about that character, to be rooting for him to succeed.
One way to make the reader care is to use motivation
(why the character wants the something) to increase the tension. If they want it for greed, that's not a good reason. But if they want it to save someone's life, that's a life-and-death reason to care.
All characters act for reasons of their own. Good characters have a good
reason for acting as they do. Bad characters have a bad reason, but ALL
characters MUST have a reason. That reason is called motivation.
So look at your characters' motivation and see if their reasons for acting as they do are important enough to generate the risks they take. Ask yourself if the reader can identify with them. If they would take the same risk, if the result can be truly devastating should the character fail.