I came into publishing just as the impact of television was really being felt. A hundred years ago a writer could stroll their way into a story. Not anymore.
Some years ago I wrote 3 chapters of a mystery and my agent sent to to Avon. After about a year they said it started too slow, (talk about slow, they can't read 3 chapters in 12 months?) the murder didn't happen quick enough. I rewrote it so the first line was "Oh damn, a dead guy."
How fast does a book need to start? Do we want the experience of being immersed in the world of the characters or do we just want the bare bones of the plot and how it all turns out?
When I first approached Sweet Cider/Bad Apple I wanted to set the scene. To me, unlike for some people who read this book, the story is not about the murder. The roots go back 30 years. It's a concatenation of events and choices that lead all these people to where they are in the present day. It's important to know this otherwise nothing can be explained.
Do we want to know why people behave the way they do or do we just want to be titillated. (I met a guy on the internet who was interested in electric devices to be used in the most startling of ways, oh never mind.) Do we just want that shock, that visceral reaction? Maybe it's a vampire screwing someone's head around on their neck. What's the next shock? How do you outdo that? Or do we want to know why people do what they do.
This is the essence of entertainment now. What are we trying to say? If nothing, okay. There's an audience for that. BIG audience. Maybe these people never get tired of Life Lite. The non-caloric, non-substantive meal that doesn't feed, doesn't nourish.
If you're trying to say something, make it interesting. Your readers will stay with you.