- Your platform - this is who you are and why you're the best possible person to write your book. For example, I'm a Masters swimmer, USA swimming coach, and certified swim instructor and therefore, have an ideal platform to write a swimming book. It's a convincer, something that gives you authority and makes you memorable.
- Your story's platform - this is a general topic of what your story is about. This is not your elevator pitch and doesn't mention specific characters or plot points. It's a general theme or subject matter that will pique interest and give you a different marketing angle. For example, Gregg Hurwitz's THE PROGRAM was about a man sent to save a girl from a cult. The book documented the methods of brainwashing, how cult leaders recruit members, etc. Therefore, his platform is simply, cults.
A solid, memorable platform lends to easier marketing strategies, which interests editors and agents. To write nonfiction, you must have a platform. How can you write about a subject if you're not an expert on it? But in fiction, having a platform doesn't always seem necessary. I've seen plenty of straightforward police procedurals that were promoted very successfully, without gimmicks or clever marketing angles. Not everyone is a former CIA agent, or cop, or lawyer. Does it help? Of course, but I don't believe having a solid platform is a guarantee for sales.
As always, your first job is to write a good story. You can have the ideal platform, but if the the book isn't well written, it won't sell. However, if your story isn't finalized yet, it's not a bad idea to think about platform during the brainstorming process. The new novel I've been working on is about tagging crews in Chicago. It's a great platform, but that alone is not a story. The story stemmed from an actual event that occurred when I was younger and the characters are based on graffiti artists I knew growing up. The platform grew out of the characters. When you have an idea for a novel or short story, explore the characters and the setting, see if there's a platform waiting to be brought out.
In these tough times, marketing is an enormous factor in book sales. You can have a well written, interesting novel, but if it's not marketable, chances are, it won't sell. The reverse is true too. You can have a marketable concept, but if it's not well executed, it won't be picked up. Writing a novel solely based on a platform is not a good idea, but creating a platform for you or your story, is.
Try brainstorming about your platform. What jobs, hobbies or subject matters are you expert in? What about you is different, interesting or makes you stand out? There is probably more there than you think.