There is no more important piece of a book proposal than the oft bespoke Platform.
A book proposal in its simplest terms is a marketing pitch for the book. It lays out the business case for your product. It's a sound product that solves a problem and we know who the market is for it, they want it, and we know how to speak to that specific market.
The platform is the last piece, that you know how to speak to the market for your book. This doesn't means the specific pitch or words, but that you already have access to the market, you have an audience of these people and it is large.
There will be whole other posts on the platform, but it declares that, for example, you have a blog that receives 20,000 hits each month, or more. You have connections in the media that have already promised exposure on Ellen, People Magazine, and a host of other popular shows. Or it could be that you are famous.
Of course, most people don't have a blog with a huge audience, aren't personal friends with Ellen or famous. This is where I come in. There are ways to identify your platform or establish one and present it in a clear and concise manner on your book proposal.
THE BIG POINT IS: DON'T LOSE HOPE. There's a way forward for everyone.