The main reason people opt-out of your mailing list is because you are not offering anything of value to them, whether it be through sample products, free information that solves a problem, or simply offering them a free ebook.

Another reason people will opt-out is because you send too many emails throughout the week and you’re cluttering up their inbox with offers, sales pitches, and things that look like spam.

Then there are those people out there who really don’t want to be on anyone’s list, and might be willing to look you up again if they need something from you.

The best way to keep them on your list is to keep them engaged, offer them true value, develop a relationship with them through personable emails, and send out just one or two emails a month unless you’re in a business where it is necessary to send more and your subscribers expect that from you.

The primary reason is usually lack of relevancy. If you are delivering great content that the subscriber asked for, then they will become and stay engaged for as long as it's relevant to them. If you have an high opt-out rate, evaluate how those people ended up on your list in the first place. Did you buy those emails or do you have an opt-in process that is obscure? If so, people may be opting out because they didn't formally ask to be subscribed in the first place. If they are true subscribers, map your content to your audience and see what messages are suffering from low engagement. It may also be time to rethink frequency. In any case, remove non-responders from your list. High opt-out rates and low engagement will negatively affect your email deliverability thereby preventing you from reaching the people who actually want to receive your email messages.

Usually it's a lack of fit. Either the content doesn't fit, the timing doesn't fit, or the expectations don't fit your recipient.

Think back to the reasons you've unsubscribed and I'm sure one of the above applied to every single one. Unless you unsubscribed by accident.

You can head off lack of fit by being ultra-clear from the beginning about what a subscriber can expect to receive from you. Don't have a subscribe widget as vague as "Receive daily updates!" Try to give them a sense of what you're offering in a few words.

Then, in the first email to a new subscriber, introduce yourself and your company and set expectations.

Tell them about the content you have planned for them.

Tell them the planned frequency of your emails.

Tell them if you plan to sell them something, whether directly or indirectly (if that's not the reason the person subscribed in the first place).

Make sure that first email reflects your brand in tone and format.

During the subscriber's stay, be sure your email content remains true to what you described in that first email. If you need to change, tell your subscribers in advance.

This way, when people unsubscribe, you'll know it's not you. It's them. Perhaps something changed in their lives that made you obsolete or irrelevant. So they ran into a lack of fit, but not because you're unfit.