For an interesting perspective on this, I'd recommend Ryan Holiday's book Perennial Seller. In it he describes the process of both his writing and his marketin

For an interesting perspective on this, I'd recommend Ryan Holiday's book Perennial Seller. In it he describes the process of both his writing and his marketing. You're not done writing when the chapter is written, that is just the start. All the editing is the time consuming part. The marketing needs to be part of the plan before the writing starts. It isn't "write a book and then sell it". He's continuously building his audience, trying to figure out what to write, writing, editing, "selling" (not actively selling, but doing the work to get feedback or get people excited about what he is writing). Repeat, repeat, repeat.