It's a fact of list life: You're always going to lose a chunk of your email list to bounces, unsubscribes, and spam complaints. In the past, you might have just shrugged off this loss—typically 30 percent or more annually—because you were able to acquire new subscribers at a much higher rate than what you lost. But your ability to do so might be getting tougher now.

With consumers getting pickier about whom they want to receive email from, along with the growing constraint caused by consumer and business spending cutbacks and the prospect of tightened marketing budgets, it's more important than ever to focus on retaining your subscribers and customers.

These three strategies can help you reduce list churn and, subsequently, boost list performance.

1. Keep subscribers active and engaged

Get subscribers engaged right at the beginning of the relationship, when they are likely to make quick decisions about their email relationship with your company. These two tactics will help:

• Manage expectations before the subscriber relationship commences. Be explicit about what kinds of email you will send and how often. Show a sample email and clearly convey the value proposition.
• Launch a welcome program immediately after confirmation. This is a timed, personalized series of emails in which you greet new subscribers, review their subscription details, invite them back to your Web site to fill out profiles or set preferences, offer special new-member promotions, etc. Use recognizable sender and subject lines to make your message stand out in the inbox.

2. Reach out to inactive subscribers

Maybe your email messages don't measure up anymore to subscribers' expectations. Or, they signed up with you to get an incentive and now regularly delete your emails unopened. Or, your messages always go to their junk folders, which they never check and automatically empty after 30 days.

For these and other reasons, a big chunk of your list is "emotionally unsubscribed." Their addresses are valid, but their attention is elsewhere. They either never clicked or clicked in the past but don't click now. Moving away from one-size-fits-all broadcast emails toward targeted and behavior-based messages will make your email more relevant and more attractive for opening.

First, segment your list to find out how inactive it is. Don't rely just on open rates, because they are notoriously inaccurate. Instead, decide how you want to define inactivity—no clicks in 12 or 18 months, for example—and create segments that fit your definitions.

Use different strategies to reach different categories of inactivity:

A. Work to reactivate the emotionally unsubscribed. Invite them to create or update a preference page, to opt in again or to opt out.

Example: Send subscribers an email suggesting that they update their email preferences to improve the value of the content and the offers they receive. Ideally, you can merge their settings into the email so they can quickly see which information or options they may want to update or change. These can also include the frequency of emails, other emails or newsletters you offer, email format, and interests and preferences (such as mountain-biking versus road-biking, or red wines versus white wines). It is important that when the subscriber clicks through to the preference page it be pre-populated with existing preferences, thus enabling quick and easy changes.

B. Survey your barely breathing segment. Find out what content they want, and consider creating personalized programs based on those preferences.

Example: Invite subscribers to complete a survey so that you can improve the value of your emails and content. The goal of the survey is to not only gather broad insight to improve your overall program but also to gain insights from individual respondents that you can use for segmentation and personalization. For example, if you believe that many subscribers are fading away from too many emails, pose questions around choosing different frequency options such as weekly, biweekly, and monthly. You can then use your findings to both modify your overall program and send emails based on subscribers' frequency preferences. These options then become part of your standard opt-in form and preference pages. To increase responses, you might consider some form of incentive that also supports your value proposition, and that may help re-engage subscribers with your email and brand.

C. Send your occasional clickers a personalized email offer. Ideally, it would be dynamic, based either on previous messages they responded to or on purchase history.

Example: A book retailer might create segments of subscribers who have clicked on certain category links (Business, Kids, Biographies, Mystery, History, etc.). Subscribers would then receive a series of emails personalized to their category of interest that would potentially include discounts or other incentives to increase purchase rates.

3. Optimize the unsubscribe process

Subscribers are more likely to unsubscribe or click the spam button when you send irrelevant email, when they don't recognize you as the sender, and when you send more email than they expected or wanted.

Your unsubscribe procedure should be easy and obvious so that people who want to leave don't think they have to resort to clicking the spam button or just deleting your messages unopened.

However, you can add functions to your unsubscribe procedure to help you retain more subscribers without making them jump through hoops, which CAN-SPAM—the US law regulating commercial email—prohibits anyway.

Not everyone who clicks the unsubscribe link wants to leave. Some want to change an email address or update preferences for content, format, and frequency.

Others do want to stop getting email but not break off all contact with your company. Give them the option to receive messages from you via other channels that you offer, such as RSS feeds, SMS, or catalogs.

Finally, for those who truly do want out, making your unsubscribe procedure easy and obvious will help them remove themselves and thus reduce both your spam-complaint and your inactivity rates.

Summing Up

Reducing list churn takes more than just increasing the amount of fresh blood you have to pump into your list to keep your email program active. If you follow these tactics, you'll make yourself more valuable to your subscribers, reduce bounces and spam complaints, and clear out the deadwood that could be dragging down your list's performance.