To some extent, a writer is a writer is a writer, regardless of what kind of work they produce. There are certain realities that every writer must grapple with (if you don't write, you don't make money; if you aren't in front of the keyboard/typewriter/pad of paper, you can't write; books/papers/copy/articles are written one word at a time) and certain techniques that every writer can benefit from to greater or lesser degree (outlining; how to break writer's block; producing a complete draft before going back to revise).
Then there are the things that make each type of writing different. For example, if I were a published fiction author (not yet, but I'm working on remedying that), I'd be reasonably confident that if a publisher wanted to reprint my work in a new format or collection, I'd be getting notified about it before it happened. Maybe not always, but most of the time -- especially if I owned the copyright to the work and hadn't signed away the relevant rights. As a technical writer, though, I rarely retain copyright on the works I produce; most of the time, they're either "to spec" or the contract with the client otherwise stipulates the work is "for-hire." On the other hand, the book advances and per-word/page payment rates are generally much more generous in technical writing than they are in the fiction world, so you're well-compensated for giving away your darlings. Not, I hasten to add, that technical writing is a way to get rich. If you are a good steady writer, are flexible in the kind of work you do, and are willing to put in the scramble to constantly line up new business, you can make a decent living as a freelance tech writer[1].
All of this is a roundabout way of saying that back last fall, I got a quick email from an editor at Windows IT Pro Magazine; she was excerpting a portion of the DCAR ebook that I did for them and wanted to know if her condensation was accurate. This excerpt was being put together as an article for the Exchange & Outlook Administrator newsletter. Other than that one email, I didn't really have any input; I may have written the material, but they own all rights to it and can re-use it however pleases them. I didn't even know they'd published it as a web exclusive article back in December until just now, thanks to a forwarded email that linked to the article down in the conversation thread.
That's pretty cool, when you think about it.
[1] Before you ask, I don't have any advice to offer. I work for 3Sharp as a full-time employee, so my other writing gigs are on the side and take up evenings and weekends. I don't know how to survive as a full-time freelancer because I don't want to know; I like my corporate overlords just fine, thank you.