Yahoo people are smart, they'll ban you if you spam there. I never tried ^spammng^ there & never see anyone siliently spamming. I was curious whether yahoo answer is the right site to get answers or not... But unfortunately I dont think it's worth. (the poll results shows opposite signs btw)
Never spam. Use this simple technique. Find the questions of your niche using advanced search. Then just answer the question as if you have had the same problem. Then just give your site name and state something like that this site helped me, etc. etc. Hope it helps.
i think you can get hefty traffic if you are posting in relevant category; because i got good traffic from that site.
Yahoo provides "nofollow" link. So you will not get any backlink from there but you can get some traffic to your site.
Traffic is good, you need just post relevant answers in relevant directories. Few answers per day. They will not give you juice, rather a good backlink.
I thought that Yahoo Answers uses the "NoFollow" attribute? Meaning that you don't get any value in terms of backlinks. You may only get some direct traffic from people reading your question/answers. But I could be wrong...