Ran across another of those "why did they do that" layout features in a book I was reading this week. In Living Like Ed by Ed Begley, Jr. (good book) there's a running footer across the bottom of the pages. It's info like you might typically find in a sidebar or little call-outs but instead it's a single line of text that runs across multiple pages.
At first, I thought it was interesting. But in order to read it you have to flip through several pages, reading just the one line (and that includes middle of sentence breaks from one page to the next). It quickly became quite annoying and it's hard to follow so that I eventually just stopped bothering with it and read the main part of the book. Why do book designers/publishers do things like that? If there is important or useful information buried in that running line I want to know it. But not if it means flipping through the entire book a second time around. But that stuff in the main body or in sidebars or in call-outs/pull-quotes or tip sections. Don't try to be too clever with a book design when the goal is to present information you want people to actually read.
There was one element that was nice. Not too long ago I was lamenting the lack of contrast between different sections of the narrative of a book. In Living Like Ed the main narrator is the author. But his wife, Rachelle, pops in periodically to give her side of the story. Her narratives are clearly differentiated with a color change, font change, and an icon. Plenty of contrast and used consistently.