The challenge for me is figuring out the return on investment. I don't mean how much I might make (although I suppose that's part of it). I mean if I have a certain number of hours per day in addition to my job and the book that I'm writing, what platform and what content is most worth my effort? It's not always easy to determine and end up stretching myself too thin, which can have a negative effect on the other stuff I want to be focusing on, like my book.