The way it's organized, you can skip chapters of shows you haven't seen, if you think you'll watch that show in the future and want to avoid the spoilers.
The book is excellent as a chronicle of changing TV from Hill Street Blues and NYPD Blue to the present day. He looks at the series from the creator/writer/show runner's point of view, making it more than a spoiler-filled exposition of what happened in the series, but rather why the creator/writer/show runner made the critical decisions that determined the direction of the series.
Also it's self-published by Sepinwall which I find brave and intriguing.