Comment spam seems to be a problem for all bloggers. I am grateful for how well this is handled by wordpress blogs. The spam filtering is done by Akismet.
Looking through the statistics for this blog, I see that there have been a total of 1806 spam, and only 82 comments that were not spam. The spam overwhelms the ordinary comments. There are only 56 actual comments showing. The remainder of that 82 have been trashed (by me). The wordpress blog has a “trash” button to move a comment to trash, and an “empty trash” button to empty that trash.
On my other blog, which has been active for longer, there have been a total of 5869 spam comments and 833 good comments. Of those, 816 remain, with the remainder having been trashed.
Akismet filtering is remarkably good. For this blog, the statistics show only 1 missed spam, and only 2 false positives. On the other blog, they show 2 missed spam and 6 false positives.
My spam policy
Thus far, I have been reading all spam comments. I read them, just to make sure that they are indeed spam and not a legitimate comment that was accidentally flagged as spam. The false positives are the comments that were actually legitimate, so I marked those as not spam and in most cases I allowed them to post as comments. In a few cases, I marked as not spam but I immediately trashed them. I’ll comment on trash policy below.
I plan to continue handling spam the same way. However, if the volume of spam becomes too high to look at each one, then I might change that.
Typical spam comment
Some spam comments are blatant advertising. There are actually only a relatively few of those. The majority are of the form of a short comment that says flattering things about the post it is commenting on, or about the blog, but which also seem disconnected from the actual content of the blog post. There is usually a web link associated with the commenter’s name, and that web link is typically to an advertising site. These spam look as if they were automatically generated, in some cases by an Eliza like program.
As far as I know, the main purpose of this spam is to try increasing google presence of the linked sites. I have only a small readership, and most readers probably skip comments anyway, so posting spam comments and expecting them to be read would be wasted effort. But posting them, so that links are left where search engines such as google will find them — that make more sense, so is the likely reason for the spam.
I mostly trash pingbacks, and most of the pingbacks are from what I have posted here or elsewhere.
If you are not sure what a ping back is, let me explain. If I post a new message here, and include a link to another blog post (here or elsewhere), then the wordpress software usually generates a short pingback comment to send to the linked post. This can be useful when people are having an only debate, for the pingback provides the links that connect the two messages.
I only trash pingbacks that I judge to not be useful.
I can only remember trashing one comment that was not a pingback. The commenter had posted the same comment twice. So I trashed one of the copies and left the other there.
The first time a user comments, that comment goes into moderation and I receive a notice. It might be several hours before I notice this, so be patient if you are caught in the moderation queue. Unless the message is spam or an unwanted pingback, I normally approve it.
Typically, second and later comments by the same poster (even to different threads) are posted immediately. But occasionally, they also go into the moderation queue. This usually happens when the comment contains several urls. Again, I am notified and I approve the comment as soon as I can (assuming that it is not spam).