As far as email marketing metrics go, email unsubscribes are more important than you might think. With all the efforts email marketers put forth to overcome barriers to landing an email in someone's inbox and, more importantly, getting them to open that email, the last thing you want is someone to unsubscribe. and unlike other metrics, the unsubscribe rate is a number you want to keep low. Make sure you are measuring it; it's critical to analyze unsubscribes from every email campaign.