I have a column for Examiner.com that I've kept up since August 2009. At first it was VERY slow moving with getting hits, but with persistence and frequent posting my readership grew. I'm not rolling in the cash, but it's a great platform. I have a topic that doesn't relate to my novels, or blog but it drives people to my other sites. As a result I have over 3,500 followers on twitter. If you're looking to supplement your income, try other venues, BUT if you're looking for a little exposure...why not? I don't just stop at Examiner, I still write other short stories, articles, etc for freelance jobs with editors and the like. The most important thing I've learned is to pick a subject you're passionate about, or else it's reeeeally hard to keep writing content.
Plus, hopefully when (if) the time ever comes for my novel to hit shelves, I'll have a wide spread group of people who might do a write-up for me. Hey, ya never know right?!