Choosing Twitter over Email to engage customers

Eric Goldman has an interesting blog post over at hit Technology and Marketing Law blog comparing and contrasting twitter and email. One of the reasons he likes Twitter is that it gives him, the ‘subscriber’ (follower in Twitspeak) control. There’s no chance that the company will sell his data. And, if the company does tweet too much that is uninteresting or irrelevant, the follower can ‘unsubscribe’ (or unfollow) without any fear that the company will override or lose the unsub request.
To my mind, the biggest problem with Twitter for B2C communication is the 140 character limit. On the other hand, it means that companies need to be clear in their language and concise in their tweets. Maybe the limited space is actually a feature not a bug.