Evolution of Blog Spam and counter measures

Captchas were very effective in stopping automated blog spams. These spam tend to clobber the comment boxes of blogs and make the links and reading it less palatable to the blog reader.
That was round one.

In the next round, we will start seeing blog spams employing spam armies that read the captchas and human entered responses to the captchas. Round two goes to the spammers.

In round three, Blog authors will run out of time to police their blog comments and will start to hire comment cops to counteract the spam armies. The balance of power will be won in round three by blog authors that hire comment cops.

There should be a business model here somewhere.