Post on forums. It's usually enough for me to get a reasonable amount of traffic for the first days of a new website. This will give you backlinks and if your website is good you can hope people will link you elsewhere. Yahoo Answers is also good if your website answers a particular question... Social Bookmarking(Delicious, digg, redit, etc.) Be creative, if you have a good website it will come. Slowly but it will come!
You have to work hard in order to get traffic. Write articles, and then submit them to article directories, use social bookmarking sites. Build lots of back links, in order to improve your rank in search engines.
I spent one month heavily on Yahoo Answers, very specific and good niche. I had 10 top replies. Never got any real traffic.
Is your Yahoo Answers too good? people won't bother to go to your site for more information, if you have already gave them satisfying answers. you have to reveal part of it and hide another part, give reader a clue and let them find it.
Try Google ,Yahoo Mail Groups... Use your Website address as mail signature. Send some of forward fun mails.
Yahoo Answers is working like a charm for me. I don't get loads of traffic but the traffic is very targeted and converts well...I guess it depends on your niche and the way you post on Yahoo! Like jim said, are your answers too good?
Submit to web directories, comment on blogs, use social bookmarking, have sig links in relevant forums, and do this regularly, also keep adding fresh content.
That's quite normal for a new site. You have to do a lot of hard work like SEO, directory submission, article submission, social book marking, getting more backlinks (from forums) apart from continuously updating your site. Good luck