It really depends on the website you want to post a link to, on the article and the comment you want to post. Depending on how they're written and what anchor text you've chosen, sometimes blog comments can be considered spammy. But, if you write a very good and useful comment, with a relevant URL to your website, the results may be really positive. On the other hand, if the comment or the website you've posted it on is not very appropriate, this may lead to the opposite effect people may still go to your website, but they may leave it soon, which will lead to a high bounce rate, which is bad in terms of SEO. So, if you rely on blog comments for getting higher traffic, think carefully what you post and what websites you post it on. For example, if you find a good article that is related to your niche, but if you see that the comments under it look rather spammy, better skip that website and don't post your comment on it.