It's very American to want to distill a product down to a choice few words in an effort to both get to the point of a thing, as well as tempt the consumer to want to know more.
Even as novels are supposed to be the enduring area where development beyond the all-pervasive 140-characters Twitter-verse is encouraged, taglines are expected.
It's also known as the "elevator pitch." Basically, if you were on a short elevator ride and wanted to describe your book to someone unfamiliar with it, how would you do so in a compelling and brief way?
So, you've just completed your novel and painstakingly pared it down from 120,000 words to 106,000. Now, go ahead and create a single line that encompasses all the magic you've created in that novel. You're a writer, it should be easy, right?
Wrong. The process forces you to remove all nuance and character development, which after pouring your blood, sweat, and tears into your work is pretty painful.
I have three "go to" taglines I use for Playing At Love, and they are most useful (where else) in Twitter posts:
Playing At Love is a glam, globetrotting exploration of the complications of friend and love relationships that will leave you rooting for the rogue(ish) heroes.
Playing At Love: A novel with music, heart and a splash of romance
Playing At Love: Sometimes you have to go down the wrong road to find the right love
None, of course, do justice in describing the main plot, let alone the subplot. Both deal with mistakes made in love, weaknesses acknowledged and eventually forgiven, all with a musical and globetrotting background. Hmm...you can see why I'm not very good with a tagline. I'll keep chipping away at it and maybe find the one that will resonate.