How spammers create fake conversational threads to bypass blog comment filters

I'm grateful that my blog posts attract lots of engaged, funny, and challenging comments.

I use Antispam Bee to automatically eradicate a couple of hundred crappy comments per day.

Nevertheless, some get through. Here's a particularly pernicious one - it appeared as three comments ostensibly in reply to each other.

At first glance these look like normal comments. They each address the content of the blog post albeit somewhat superficially.