In a recent article titled 10 Free Ways to Drive Traffic To Your Website, I mentioned using Yahoo! Answers to funnel targeted traffic to your pages or offers:
Go to http://answers.yahoo.com and find questions related to your niche or website. If you can provide a legitimate answer to their question, you can include your link as the resource or reference URL.
Kelly McCausey pointed out to me that there is another new Public Opinion/Q&A site called Askville, which is a beta start-up by Amazon.com. In fact, she has a Squidoo Lens that will give you all the details: Askville Lens...
The great things about these types of sites (Yahoo! Answers, MyLot, Askville, etc) is that you can 1) use them for live market research, and 2) communicate directly with your target market on a micro-level.
These sites feature discussions on medical topics, entertainment, business, parenting, pets and practically anything else you can imagine. No matter what niches you work in, you will find your target audience asking questions - and more than willing to answer them as well.