I just cleared out a bunch of comments that were being held for moderation. The spam filters I have on this site work pretty well. Nothing gets through them. Unfortunately, legitimate comments from first-time commenters are almost always held for review.
Most of the spam comments are just link spam. Someone, probably a bot, posts comment filled with links to other sites. They do this so that they will get better ranking in search engines because it looks like a lot of sites link to them. Easy to stop.
The ones I laugh at the most, though, are the ones that sound like a sincere message from someone who want to help make my site better and get better placement in search engines. The tip off that they haven’t even looked at my site is they always talk about improving my site to make more money. Ha. Money is the last thing on my mind here. But they think that I need their service to improve my SEO – or Search Engine Optimization.
I’m convinced that SEO actually means SnakE Oil.