Ah. Yes. Well, there's more to selling a novel than writing a query letter.
The One Sentence Logline is basically a pitching tool. It's the thing you rely on when someone says "Oh, you're writing a book? What's it about?" It doesn't matter if that someone is your great-aunt Matilda or an agent you bumped into at a writing conference. The last thing you want to be doing is groping around for an explanation of what your book is about. (And we've all been there, right? "Well, see. There's this girl. And she's magic and live in Ireland. Only it's not called Ireland, it's called Eire because the British never succeeded in invading in the 1600s. And she's lonely and then she finds out that her dad is in trouble and she wants to help him...." And then it gets really messy.)
Also, if you're a writer who has been on Twitter with any frequency over the past year you've probably run across a Twitter Pitching contest or two. (This goes ten-fold for YA writers who frequent agent blogs.)
The Twitter Pitch is even worse than the One Sentence Pitch because whatever sentence you come up with has to fit in about 132 characters. I know. MADNESS! But useful madness.
Here are a couple I used during #pitmad a few months ago.
A young magic-handler desperate to find her Da confronts conspiracy, murder and forbidden magic under the streets of 1888 London.
With a brutal serial killer loose in London and a werewolf as her ally, Keira Fennel will save her Da or die trying.
Keira Fennel didn't plan to run away or put her trust in a stranger, but Da's in danger and death nor magic will keep her from him.
I had a few others, but they were multi-sentence pitches so I'll save them for the post on Three Sentence Loglines.
"Well, that's cute," you say. "But I don't intend to enter any pitch contests and I certainly don't have the money to go to a writing conference and hobnob with agents. What good will this do me?"
If there's one vital ingredient to selling something it's KNOWING YOUR PRODUCT. It's no different when we're talking about a novel. And distilling the 400+ pages of your book into one concise sentence, one through line that will tell anyone the heart of your story, is immensely useful. Especially if you use it as a building block for other tools to pitch and sell your novel. (More on this later.)
Holly Lisle even recommends finding the logline as part of of the editing process. Before you even cut the first word, find the logline. It's the heart of your project. The statement you can hold each chapter up to and say "How does this fit with the theme/heart of my book?"
"Okay," you say. "I might be able to use that. But how do I write a logline?"
With great difficulty. Hah. There's no perfect way to tell you how to find that single sentence summary of your story, but here is a great template (courtesy of Authoress courtesy of Holly Bodger).
"When [MAIN CHARACTER] [INCITING INCIDENT], he [CONFLICT]. And if he doesn't [GOAL] he will [CONSEQUENCES]."
Notice that she suggests two sentences there. But for this structure, one will usually work as well. Write a logline for your book based on that structure, then start playing with it.
Try and make it as effective as possible in the fewest number of words.
Try putting the goal and consequences first.
Use active words. (Verbs are your friend.)
Assign an adjective to your MC (plucky or reluctant or young or... you get the point).
SAVE EVERY VERSION. (I have a journal I use for brainstorming these. It goes through many pages just to get one usable logline.)
Consider how to pitch the story as a romance. A thriller. An action-adventure.
If you stick with it, something will click. (It might take a few tries, it might take dozens.) Stick with it.
This will be one of the most important tools you can use to sell your novel.