For those unfamiliar, Demand owns eHow, Answerbag, and a handful of other sites that offer content and advertising. Sounds like a newspaper or magazine, right? Well, not exactly. The content on these sites is determined by what people are searching for, and is populated by people who can do a modicum of research and can string a couple of sentences together.
Danny Sullivan explains a little more about their revenue streams, but basically the way this works is that you search for something like "how to string a tennis racket" and Demand Media's computers say, "We could own that." So, "How To String A Tennis Racket" gets added to a list of articles available. It gets assigned a type of article and site, and based on those, a price point they'll pay for the article.
Someone who has been accepted as a writer says, "Hey, I could write that," and does. The article goes to a copy editor, the editor accepts the article or sends it back for rewrites, the writer either gives it up or re-writes it; if the article is re-written, the editor either accepts it or rejects it. If the article is accepted, the writer gets paid.
You may have guessed by now that I've done some writing for them. I'm not particularly proud of that writing, and don't generally include it in portfolios or writing samples because it's really mediocre work – the whole model revolves around the articles being relevant to searches, rather than enjoyable, in-depth writing.
But by and large, if you're asking how to string a tennis racket, you want to learn how to string a tennis racket, and if the piece is good enough to get that done, frankly, it's good enough to get it done.
I'm writing for them because they pay, and if you know how to do the research, they pay well. While $15 for a 400-500 word piece (call it 3 cents a word) is far less than a good publication would pay, it's far more than their competitors (Textbroker, for example, pays about a penny a word to its most highly qualified writers, and about a half-cent to its writers who demonstrate mediocre grammar skills).
I type in the neighborhood of 90-100 words per minute, which means that I can do the actual writing for an article for eHow in under 10 minutes. If I add 10 minutes for the research, I just made $15 for 20 minutes worth of work. Grab 3 or 4 articles that can be written on the same research, and you can clear $50 an hour for working for Demand. That's pretty good by any publication's standards, even if you're not racking up a portfolio you can be proud of (let's face it, even quality publications need someone to write up unremarkable content, and they do it for more like $8-$10 an hour).
So yes, you're definitely losing some quality in exchange for relevance, but that's been a problem on the web since before someone thought up the content farm idea. Journalism itself has fallen victim to the search engines to some extent. But frankly, if I want to know how to file for a copyright, I don't need to be wowed by the prose. Just tell me what to send where and how to figure out how much it's going to cost me.