Humans make very good script engines, too. If you need to put out a script but vary it to get past simple algorithmic spam filtering, you can't beat running it

Humans make very good script engines, too. If you need to put out a script but vary it to get past simple algorithmic spam filtering, you can't beat running it through a good hardworking human who can type real fast and think on the fly. That human's doing the job of a bot, for all practical purposes: 'bot' is a job description, and humans can easily outperform computers for some bot purposes. For now :)