You know – my email is full of spam. So is my regular mail box. People got tired of spam long ago. More than 80% of internet is spam so don’t produce more. Comment spamming can frustrate many bloggers.
On the other hand link building is important for every starting web business. You need some initial amount of links to be discovered by readers. Popular SEO advice is to post comments on blogs in your niche. You’ll see this advice in many "top 10 link building tips" posts. And it is not so bad to use it. Just don’t post junk content. If you intend to post something like "Cool blog", "Very good post", "Good point" or etc please stop. Your comment will be deleted from almost everywhere. Posting such comments doesn’t pay back – you will lose your time and won’t get anything back.
Comment only if you want to say something about the post/blog topic. Say something interesting, not just crap. Cool comment on a popular blog can bring you tons of visitors.