Hey guys, I saw this thread and thought I'd add to it.
Below is something John Marco wrote to me. It's simple, but means a lot.
Let me try to answer your question in the simplest way I know how. Every scene in a book needs to be dramatic. By that I mean that every scene needs to move the story forward. It needs to reveal something about the plot or about the characters and how they think and feel. Drama doesn't mean jumping up and down, though--drama can be quiet. But it needs to be advancing the story and telling the reader something important. It can't just be a "set piece" to show off something cool. Each scene must matter.