Apologies to the author. This book is really good for what it is. It's honestly exactly what I wanted: a primer with several practical examples, to teach the background, the basics, and the nitty gritty. If you need to understand how GTM and GA works through and through, this is a great book for you! I not only would, but do recommend it. I brought my copy into work and regularly have my team reference it as they work.
The only reason I gave it three stars is because it's not exactly the kind of book that I would add to my best-books-ever shelf. I liked it. But it didn't change my life. (Surprisingly, some programming books have!) That's not what I expected of this book, but that is how ratings work on GoodReads. I should probably go to Amazon and give it a five star rating, because it's deserved.