What's With the Titles?

So I read Zen and the Art of Vampires, which starts out rather poorly. Some of the lines were so ridiculous that I bust out laughing at them. But then, something happened mid-way through the book and I finished it wanting to know what was going to happen next. The second book, Crouching Vampire, Hidden Fang is the follow up to the Zen book and now I'm hooked on Katie MacAlister's books! She combines vampires, called Dark Ones, and the Brotherhood, which is an organization that kills Dark Ones in Iceland where our heroine, Pia Thomason, is vacationing. Pia ends up becoming a Zorya, which is someone who helps ghosts pass over. In the book, Sex and the Single Vampire, the heroine Allegra Telford is a Summoner. Allegra and her Dark One, Christian are also in the Crouching book. Her heroines are flawed, in their own eyes in some way. Pia is too curvy for her own comfort and Allegra's eyes are two different colors and walks with a limp. The men they fall in love with are devastatingly handsome. The two women meet their men and are their Beloveds, which means they return their soul to them and they can communicate telepathically and the sex is really, really good. Fun, light, summer reads.