The term “active” is thrown around pretty loosely when it comes to individual email addresses, and its definition can often vary wildly depending on which camp you are in: ISP, ESP, or marketer. We can all agree that customer activity and engagement is one of the most important factors of having strong deliverability. Then why aren’t we all taking action to make sure all subscribers on our lists are truly “active”? Why the fear of cleaning our lists?

Sometimes the hesitation is caused by old-school mentality from catalogue marketers: more mail = more money. Similarly, it can also be because of outdated ad revenue models where the larger the audience, the larger the ad revenue. While this still holds true in some cases, ad buyers will soon begin to negotiate pricing on delivery/deliverability numbers and not just volume. Another common problem is that those in a position to recommend changes may be rejected by uninformed management. What you must understand is that the receiving mail server doesn’t care about your business model or what your management team considers an “active” customer. The algorithms are what they are; “MTA 1.X.3” will not engage in a philosophical discussion with you on the matter.

While I wouldn’t attempt to define “active” recipients for an entire industry or a vertical, I can propose some basic principles to consider that should simplify things. Let’s look at several scenarios, all of which I hear regularly defined as “active users” and decide how active they really are. Along the way, let’s keep track of the number of unread messages. Marketers must be conscious of certain milestones in activity (or inactivity) to both ensure clean lists and drive engagement. Ideally, each one of these milestones should drive a triggered email.

Active User No. 1 – Open or Clicked in the Last 30 Days

I don’t think anyone would argue this is a recently engaged user; for most mailers, this is still well within the realm of a brand new customer or post-purchase lifecycle. But over the course of just one month, significant inactive volume can build depending on frequency.

Messages sent to date:

1/week = 4 emails
3/week = 12 emails
7/week = 30 emails

Milestone. No activity in 30 days. Check in, whether it be updating preferences or a stronger offer. Know that after 30 days, you may already be losing them.

Active User No. 2 – Open or Clicked in the Last 3 Months

Now let’s put this in perspective. Depending on the frequency of your mail stream, it could be totally normal for a customer to not open and engage in this period of time. Biweekly travel deals are a good example. Most customers won’t be traveling every other week, but the cadence isn’t overwhelming and it’s understandable to treat this user as active based on your lifecycle. If you mail daily, however, you have a different issue on your hand. In 90 days, you have sent 90 emails, with zero response. It may be due to over-mailing or it could be just that you have sent too many offers for something they don’t buy very often. For example, if you sell high-end TVs, chances are a customer who bought a 60″ HDTV probably won’t be buying one tomorrow, unless they’re furnishing a new sports bar.

Messages sent to date:

1/week = 12 emails
3/week = 36 emails
7/week = 90 emails

Milestone. No activity in 90 days, but purchased. You know they bought a TV, so why not send something about calibrating it properly or a new universal remote? Don’t ignore your customers’ prior purchase history, unless you want them to be one-time buyers.

Active User No. 3 – Open or Clicked in the Last 6 Months

This is the point where you should be considering a significant shift in thought and cadence. First things first. Stop calling these subscribers active, even if your business considers these customers active from a purchase perspective. When it comes to email and engagement, this is not active. Would you consider yourself an active person if you exercised once every six months? Maybe so…but your doctor would probably disagree!

Messages sent to date:

1/week = 24 emails
3/week = 72 emails
7/week = 126 emails

Milestone. No activity in six months. If they have purchased in the past, it’s time to adjust frequency and content to suit. Better yet, ask them if they would like to receive communications through other channels, such as text message or traditional mail. If they’ve never purchased, it’s time to start thinking about cutting the dead weight. These people will impact your deliverability regardless of purchase history and prevent you from reaching your truly active users. Consider a reactivation campaign asking subscribers to opt back in with a strong offer. If they still don’t engage, drop them.

Active User No. 4 – Open or Clicked in the Last Year

This seems to be the cutoff point of active for many marketers. I’m sure when they’re sending the email, they get the same feeling I do when I buy a lottery ticket: “Today is the day!” Sadly, I still haven’t won.

Messages sent to date:

1/week = 52 emails
3/week = 156 emails
7/week = 365 emails (366 for those that ran that leap year sale, which they didn’t open either.)

Milestone. No activity for the last year. It’s time to say goodbye to the truly inactive, and attempt to save the past buyers, depending on your customer lifecycle.

Active User Definition No. 5 – 2 Years Active

Believe it or not, I do hear this duration used as “active” from time to time. This is where you have the real potential to fall into spam traps, or deliverability quicksand. If you qualify this customer as active with a straight face, it’s time to change professions. If you want to call something that hasn’t done anything in two years “active,” there is already a profession for you…volcanology, the study of volcanoes.

Messages sent to date:

1/week = 104 emails
3/week = 312 emails
7/week = 730 emails

Milestone. One last chance for reactivation. You should have done it already a year ago, but better late than never. If they don’t explicitly ask to stay on the list, say your goodbyes. Anyone older than that, don’t bother.

These are not hard rules, but hopefully good guidelines to help you define appropriate intervals as part of your data selection process. As marketers, it’s your responsibility to know your audience and communicate it to those who build them (don’t expect them to do it for you – it’s not their job or expertise!). So next time you request a list of “active” users, make sure that you’re asking the right questions to clearly define those criteria. Then go out and buy that lottery ticket.