I have found that a lot of "writers" can't write at all, but a true content writer can write a general article about anything in the world. It is a matter of research, organization, and doing their thing.
Here is the problem I find. They write what they think is best. This can result in a great article that doesn't say what you want it to say.
When I have an article written (by a good writer) that I have given an outline to about what I want, I usually get a much more on subject article.
But when it comes to in depth, detailed articles about a subject, the writers unfamiliarity with the subject shows. When writing a very technical article on the subject, they do not know the jargon, and someone in that field will spot it instantly.
(for instance, I used to work heavy construction. Recently a building collapse killed some people in the USA, due to a heavy equipment operator using an excavator incorrectly. All the news organizations reported that a "crane operator" using an excavator had caused the building collapse. Crane operators do not operate excavators, they operate cranes. This is a very small point of contention. but anyone in the heavy equipment trades recognized it instantly.)
The question is, as with any content is: "Who is your audience?". If your site is for general information, outsourced articles are a good choice. Even when you need a technical article, you can often find a writer who you can outline what you want and get a good article.
But when I do have a very technical, or in depth article, I have it written, then re-rite it myself.
I have what I refer to as a "jump start" problem. When I am faced with writing an article, I sometimes do not how to get started. If I read someone else's work it will usually give me the jump start I need.
To that end, I use a program called "rankyzscrapper" (I think I got it on this forum). I put in my keyword, and it downloads articles. I find a few with the subject matter I want, then use a program called "article reviser" to parse and re-write the article, or simply use the source articles as inspiration for my writing.
Another benefit of doing this is that often I find a salient point in these source articles that I had not thought of myself.
All of that being said (like Navavlad said above me), I do not write sales copy. Content articles are one thing, sales copy is a different world.
