I've noticed that you often differentiate between two different kinds of freelance writing: "biz tech" and "journalistic." How come?
I credit the National Writers Union for this breakdown of genres. Actually, their website has a link that divides writers' work into three genres: books, journalism, and business-technical writing, along with a Poetry link. Of course, About.com has sites that are completely dedicated to writing fiction and poety, leaving us to deal with the two main kinds of freelance writing: "biz tech" and "journalism."
Thinking about what "I'm a freelance writer" means, you'll notice that most freelancers stick to one or both of these categories; they either write copy for companies, websites and the like, or they spend their time researching their passions and writing their own articles to sell to magazines and newspapers.
Of course, this isn't an exhaustive list, and I know many freelancers who stick almost exclusively to pitching book anthologies, writing speeches, or selling poetry.
