I've been getting spam comments, and I've decided to implement a policy that will help reduce those comments. A common practice among spammers is to choose comment IDs that advertise commercial products. The spammers often leave general comments such as "This blog is great", and their comments include their IDs which are links to their commercial sites. All persons who visit this blog are invited to leave comments about their experiences with science and religion, but comments that include links to commercial products may be deleted.
If your Google ID links to commercial products, I suggest that to avoid the risk of having your comments deleted, you comment with your personal name (not your company name), or that you log in Anonymously to post your comment.
In addition, comments that put links to commercial products in the text of the comment may be deleted.