When you are trying to promote and build back links, do not comment on older post or spam blogs. I get this a lot on one of my blogs, and I have to go in every day and delete spam comments. It is annoying for site owners and if they find your comment-they will delete it! Yes, as a blogger I go through this everyday. So I just thought I'd let you know that your efforts are fruitless for you.
Spamming is never good for Anybody. Not for the Website owner not for the Spammers. It can give you short term boost up in traffic or search engine ranking. But if you need to keep it you need quality. Relationship what you need to build when commenting. Otherwise you can be blacklisted from blogs. Now a days Spam control system is much better than 90's. So start being a white Hat.
open my blog everyday, and then see the useless pingbacks, then delect them, really adds my workload, and also does no help to the spammers. so i really advise not to spam in others' blogs.
The intellectual spam is won: 1. Dot removal with blocking on ip. 2. Personal addition of each separate comment. From more unpleasant decisions it is possible to note: 1. Openid-support with possibility of blocking of all domain. 2. Acknowledgement on e-mail. And much backlinks it is possible to receive if to register the blogs in such communities, as: Technorati, MyBlogLog, Blogcatalog, Blogged.