1. Delivery Rate
Not every mail reaches the desired destination. Various reason are responsible for this: the receiver's inbox is full or the mail address is not correct etc.
The delivery rate of your mails should be high. If the rate is below 95% it is time to have a look at your contact list and do some cleaning up!
2. Open Rate
The open rate tells you how many people actually opened your mail. 20 percent is a good mark. Should your rate be significantly below the 20 percent mark, you should think about you subject lines and content in general.
Be that as it may: the opening rate does not tell you how many people actually read the mail.
3. Growth Rate
More contacts usually equal more clicks. The number of contacts is not the single most important criteria. Yet you should still pay attention to it as you can generate more conversions with it.
You pursue an objective with your newsletter. You want your readers to click on a specific offer. That is why you have to pay attention to each and every link in your newsletter.
However, do not solely mind click rates, but also where certain links perform the best. Links at the beginning of a mail are usually clicked much more often that links at the bottom of a mail because many users do not read the whole mail.
5. Conversion Rate
The most important criteria is the conversion rate. This stat refers to the number of people who have completed a contact form to access additional offers, such as a whitepaper download or a registration for a webinar.
It is not suffice to simply forward the reader to a blog post. As the purpose of your newsletter is to convert users into paying customers, it is important to continuously supplement his or her contact profile with valuable data.