I too got carried away by the promise of blog traffic by commenting on blogs on similar niche. It is a big waste of time. After all, how much traffic you can expect from the links you place along with your comments?
These, comments are not welcome by experienced bloggers. New bloggers might be too eager to approve all the comments including spam comments in order to attract more comments. Slowly, they will see the futility in blog comments.
Blog comment is very useful in getting quality inbound links provided, if you place your comment and a link to your blog in a "dofollow" blog. Well, out of that, you may get a trickle of visitors.
These days, I am seeing only messages in my blog comments that I promptly mark as spam. Paid blog commentators use my blogs as message boards. Their few nonsense words will not reflect that they have read your blog post.
I believe several professional blog commenters are using automatic blog commenting software.