Prototyping ChaBoT

For the last year or so, I’ve sporadically wondered about whether there would be any benefit to be gained by conducting a CBT-ish (structured? informed?) conversation with a non-human agent. CBT is highly structured and its activities frequently serve as therapy homework, i.e. you can do them on your own. Talking to an agent obviously wouldn’t have the same effect as talking to a human therapist, on the other hand, what would the effect be?