Subscribers come and subscribers go and while it’s sad to say goodbye, that is the nature of the email marketing beast. List churn is a fact of life, but it’s important to keep a sharp eye on the key data points that will give you clues as to how serious (or normal) you list churn actually is. Here are three metrics you should pay attention to with each deployment: Hard bounce rate: How many bad addresses do you have on your list? Automatically remove these addresses when they bounce once, but also try to identify the source. If people are putting in fake email addresses, implement a verification system. If it seems like bots are the culprit, then utilize a system like Captcha to humanize the experience. The average bounce rate is around 2%, but good mailers have averages far below this point. Try to be one of them. Unsubscribe Rate: How many people are politely removing themselves from your list? Average unsubscribe rates are around 0.3%. If your rate is higher, then this could be an indicator that something is wrong with your content. Look for trends so you can isolate the cause and make improvements. For example, if you sell baby clothes, then you may find that parents opt out of your emails when children reach a certain age. That is natural, but if you are an all around retailer, then you may need to think about adjusting your offer. To see a breakdown of unsubscribe rates by industry, take a look at this blog post. Complaint Rate: How many people are reporting your email as spam? High complaint rates not only ruin your sending reputation, but also impact your delivery. Each ISP has their own threshold for complaints, but top senders don’t suffer from this problem at all. If you have a high complaint rate, check your content and also the placement of your unsubscribe. It could be that by making it hard to find the unsubscribe feature in your email, you are forcing people to report you as spam to get off your list. If you want to learn more about email delivery best practices, download our free Deliverability Guide.