For those of you who have published non-fiction titles, do you mostly write on spec or are you commissioned to write specific books?
For those of you who have had something you wrote on spec accepted and published, what do you think sold it (e.g. topical subject matter, finding a niche, etc.)? Did you write your book and then find a publisher, or did you write with a specific publisher in mind?
For those of you who are currently writing non-fiction but have not yet been published, do you have a particular publisher in mind? Are you just writing what you want or need to write or have you identified a niche or a particularly popular topic?