If the subscribers aren’t responding to your emails (not reading or clicking through them), is it okay to email them? The short answer is no, because email marketing is a two-way conversation, and emailing to disinterested customers is everything but one-way communication.

You can, however, try and deal with non-responsive subscribers. That will ensure that your business isn’t harmed by inactive subscribers. Furthermore, you can re-engage some of your inactive subscribers with a win-back campaign.

(Before we start, remember at all times that not everyone who doesn’t open an email will start hating you. The subscribers will just wait for an email which captures their attention… or maybe they just hadn’t the time to read your emails, or had a messy inbox and chose the easy way out (mark and delete). People have their reasons. One or two unread emails don’t mean much.)

The ways inactive subscribers can “harm” you

There will always be subscribers who’ll ignore your messages for months and mess up your statistics, making your campaign less effective. But that’s not the worst they can do.

The very real threat of non-responsive subscribers comes from spam complaints and dead-end emails.
Inactive addresses are often turned into spam traps by ISPs, and emailing to those can make your whole campaign plummet in a matter of weeks. Furthermore, angry subscribers will often mark your email as spam, simply because they think that this means “unsubscribing”, thus causing further email deliverability problems.

Besides, email prioritization systems like Gmail’s priority inbox (something alike it will supposedly be included into AOL’s Project Phoenix, and is already found in Hotmail — Sweep) have already went to mobile phones, and will directly influence open rates in the future.

You can stop email from moving onto a lower priority for individuals by making it more interesting to the subscriber, but remember that your emails can automatically move to a lower priority because of global email prioritization. That’s how inactive subscribers, especially in large numbers, will leak your campaigns, and make them less and less effective.

What to do – purge the list of inactive subscribers, or try winning them back?

Purging is some times a more viable option, contrary to what you might think. Obviously, wasting time and content for a small number of inactive subscribers, like 20 to 100, isn’t worth it unless you run an enterprise with a high customer/value projection. Purging is also recommended for rarely cleaned email lists, because sending to most likely obsolete emails can further damage your brand.

For bigger email lists purging versus winning back is not an obvious choice, and you should carefully weigh the pros and cons, because the more emails you send, the more the campaign will cost, but there is always the chance to win back customers who’ll earn you money for years to come.

In many cases, however, you shouldn’t throw inactive addresses in the wastebasket just like that.
Try decreasing the sending volume to them at first, but if that doesn’t work, and if re-engagement just doesn’t seem viable, send them a “farewell-email” confirming the subscriber’s unwillingness to participate in the list should be sent.

If, however, you want to re-engage your customers, a win-back campaign will help you.

How an effective win-back campaign looks like

Return Path posted an eye-opening report on the subject some time ago. The report has quite a few examples of good re-engagement strategies, but the main idea is as follows:

1. Start your win-back campaign by defining who exactly are your inactive subscribers.
This can vary depending on your niche, the amount of your subscribers, your email sending volume, etc.
The easiest way to segment inactive users is a set timescale – if a respondent hasn’t opened an email for some time (you have to pick it depending on the frequency of your emails), assign the user to the ‘inactive’ segment.

2. Grab the subscriber’s attention with an attractive offer, or a series of particularly attractive emails.
Skyrocket the response by giving the subscriber incentive like a coupon, a free download, free shipping for orders, or a contest, that brings the customer back to you.

3. Terminate all non-responsive emails, or send a re-subscribing email, which requires action to receive further email from you.
The re-subscribing email should be your last resort. Let the subscribers know that, at a set time, you’ll remove them from your list due to inactivity, and, of course, honor their choice by removing them from your mailing list.

In the end – Enjoy a more effective mailing list.

What to take from this

Much like unsubscribes, non-responsive subscribers tell a lot about your campaigns, usually in the email relevance or frequency field. Keep in mind that there’ll be factors you cannot influence, and losing some subscribers is inevitable, but if your inactive subscriber counts fluctuate, it may serve right to revise your content policy and email sending frequency.

It’s up to you to decide whether you need a win-back campaign, but if you commit to a plan, stick to it, but, most importantly, always know how to say goodbye.