What an enchanting read! Not knowing a thing about this book before I started made it all the better. For instance, I was unaware that I was essentially about to read a fantasy novel. Clearly any book that makes magic real is by definition fantasy. Even when it's clearly rooting itself in the not-too-distant past of our own world.
Speaking of which, I completely missed some of the telling signs Morgenstern was truly throwing at me regarding the origins of the circus in general, and the circus as it exists in our present-day minds. I will give nothing away just in case others are as slow as I was to get the hints. But I will say that they are just hints, and that she doesn't fully realize them (as she shouldn't in a fantasy novel).
Don't let the number of pages dissuade you, as this book moves very, very quickly. I think I finished it in 4 days (granted, 4 vacation days) and was compelled to return to it as often as possible. The writing is a little formal, however, this fits well with a book set in the late 19th century. It also has a slight goth feel to it - the black and white circus tents, the ultra-chic dresses, the slow-moving statues, the "reveurs" and their flashes of red - and I believe that makes it all the more interesting.
I was told not to read the back of the book. I read this on Kindle so didn't have to worry about that, but in seeking out the back cover after I was finished I didn't see any monstrous spoilers - nothing that wasn't guessable from the get-go. Perhaps I saw the wrong back of the book.