After more reading about this, using Quora looks to be good for Quora unless your answer is spot on, a winner and has offered extended answers at your site.
If you are just on that site to spam, you may not see any hits.
PS. On another forum I'm now getting requests from OPs (original posters) because their spam posts are resulting in negative moves in their SEO. So random postings with links can have the opposite of the intended effect. Be sure to find SEO discussion forums about that.
Yes, I use. I find my target audience, post helpful comments and create my own topics. This brings me traffic.