First a girlfriend suggested it, then my Pastor preached a series on it, then Barnes & Noble had a Groupon. I really had no excuse NOT to get this book.
This book teaches what speaks to you and how you can figure out what speaks to people with whom you interact daily (roommates, coworkers, parents, sigfigs, etc) to strengthen your relationships.
I found the love language profile particularly helpful to figure out what my secondary love language is, my primary one was already obvious to me. This book has 14 [easy-to-read] chapters, but you really only need to read the first 8 to grasp the concepts.
The last note I'll make is from my Pastor. He said while all of the love languages are good and necessary, if you require someone to constantly speak to you in each language, then you want too much. (Of course, he had a whole sermon and I just have a sentence, so I can't really elaborate like I want to.) I thought it was interesting to note that he said by asking for too much you can make yourself "difficult to love."