Some days i get a great response and others nothing. I think it really helps to provide insightful comments along with your link. Don't just go in there copying and pasting the same text into every answer. Many of my answers have been chosen as the best answer, I think you should try to get the best answer too to help prevent getting flagged. I've definitely answered too many answers in a day and they prevented me for answering any more for a day or two. So be careful, i guess do 20 or less as someone else said.
Yahoo Answers is good for the long term....if you can have your answers selected as the best, and become the top answers provider in one topic.
If you post too many answers with links to your site and if some user reports, then you will get banned. So use Yahoo answers with caution if you want to do it for long run.
I'm using the same strategy When I do have time and when I write a new blog post then I search on Google and I do post comments on relevant blogs or Yahoo Answers