There's one thing that irritates me a lot about web content writing. Ok, there are several things, but let's start out with one for now. It seems a little strange for so many potential clients to want a sample that exactly relates to their subject. Like, even if I don't have an article sample about vacationing in Sarajevo, that doesn't mean that I can't write one.
If someone is a reasonably talented writer, they can write about just about anything. My samples are samples of my writing style and ability. They are not a sample of my precise knowledge on any subject. And even if I do have a sample about a certain topic, it's a sample that I wrote on one aspect of the topic. If it doesn't have the exact information someone is looking for in a sample, that doesn't mean that I don't know more about the topic. It simply means that every article is different and every perspective is different. There is no legitimate reason for writing samples about every possible topic and using them to simply regurgitate every piece of information you can find. That's crap, not writing.
If someone can write, then they can write. Period. Another thing some potential clients do is to look at your samples, see that they look fine, and then ask you to write another sample about their topic. Um, no. My samples are there to show my ability- not as a proposal to do free work. I hope my samples show that I can do my job.