There is a school of thought that says you should niche down and become the best at one thing rather than spreading yourself thin. Some freelancers have built very steady careers doing just that, offering one service to a specific type of client and doing it really well. The risk, of course, is that demand for that skill could drop or the market could shift. But focus can also be a strength when done right. Do you think one skill is enough to build a lasting freelance career?