My husband brought this home recently, as his editor passed it along to him (presumably because he's the only one in the office who qualifies as a newlywed). Having been married for six months, one quick glance through this book suggested that we're already a bit beyond this book's demographic; one thorough read, in fact, verified such a notion.
Don't get me wrong, it's packed with useful tidbits. But the target audience for this book seems to be either couples who didn't start living together until right before or after the wedding (we'd been living together for almost three years by the time we got married, so we figured out most of this stuff on our own) or couples who are getting used to the fact that they're acting as one half of a functioning unit.
The points it makes ARE important. But they're also things that should come as either common sense or common courtesy in the context of a healthy marriage. You need to know how to argue productively. You need to know how to budget. You need to be aware of your spouse's feelings. And you better as hell know where you both stand in regard to the future. But when making each other laugh comes as naturally as frequent (and healthy) discussion, you also don't need to be told how it's all done.
While this book fell into our hands way after its relevant usage, I can see why a fledgling couple who only recently got married or started sharing a living space may find it invaluable. The end of the book does have some crucial information that delves far beyond the newlywed time frame (like the frequency of medical checkups as you start growing old together), the date ideas are adorable, and the anniversary gift suggestions are uniquely sweet.
I feel like this is the kind of book that gets passed among friends and sisters as an attempt to help ease the transition into married life.