Thoughts on Data Hygiene

zombieemailOne of the big deliverability vs. marketing arguments has to do with data hygiene and dropping inactive users. Marketers hate that deliverability people tell them to let subscribers go after a long time of no activity from the subscriber.
Data hygiene is good. Email is not permanent and not forever, and the requirements for data hygiene in the email space are very different than the requirements in the postal mail space. There is no such thing as “dear occupant” in email. I mean, you can sent to occupant, but the occupant can then hit the this is spam button. Too many emails to “occupant” and mail goes to bulk instead of the inbox. These are real risks.
With that being said, there are a lot of things to consider when putting together a data hygiene program. You’re looking to remove people who are no longer interested in your brand as much as they are no longer interested in your mail. You’re trying to suss out who might have abandoned the email address you have for them. It’s complicated.
I’ve worked with a lot of clients over the years to implement data hygiene programs. Sometimes those programs were to deal with a bulk foldering issue. Other times clients have been trying to address a SBL listing. Still other clients were just looking for better control over their email and delivery. In all cases, my goal is to identify and classify their recipients into 3 groups: addresses we know are good, addresses we know are bad, and then addresses we don’t know about.
Good addresses get mailed. Bad addresses get dumped. The challenging bit is what do we do with the unknown addresses? That’s when we start looking at other data the client may have. Purchases? Website visits? What do we have to work with and what else do we know about the people behind the addresses. Once we’ve looked at the data we design a program to take the addresses we don’t know about and drop them into either the good or the bad bucket. How we do that really depends on the specifics of the company, their program and their data. But we’ve had good success overall.
There’s been a lot of discussion on hygiene this week, after Mailchimp published a blog post looking at the value of inactive subscribers. They found something that I don’t find very surprising, based on my observations across hundreds of clients over the years.

[T]he data backs it up: An inactive subscriber is a better customer than a non-subscriber.

This actually came up at the MessageSystems Insight Conference in Monterey last year. One of the MailChimp guys asked me about pruning during my talk. Afterwards, we had a conversation at dinner. He said MailChimp was looking at changing their recommendations and asked my opinion on the blanket ‘prune your subscribers’ recommendation. Specifically he wanted to know what I thought about it in the case of retailers.
I told him I’d never held on to the idea that a company should just prune subscribers from a list in the absence of delivery problems. If the users are not hurting delivery, there really isn’t a reason to drop them. Remember, ISPs measure engagement differently than marketers, so they may be engaging with the mail in ways senders can’t track.
I do think there is some point where a sender should give up mailing, but that is really going to depend on the sender and their process. Newsletters vs. advertising vs. retail vs. e-commerce have different customer and product lifespans.
What you’re selling matters, too. Cars have a different lifespan than light bulbs or toothpaste. If you’re selling something with a short interval and a customer hasn’t purchased in 4 or 5 or 6 cycles, maybe you should decide this isn’t a customer any longer. But if you’re selling cars someone may wait 4 or 5 years between purchases.
There’s also the data you started with. How did you initially acquire the customer? That also impacts how an address affects your deliverability. Some subscription pathways are going to be riskier and should be taken off your list sooner than others.
As with everything in deliverability, there is no one answer to when to stop mailing an address. It really does all depend on the specifics.
I’m glad MC did the work. I didn’t know our conversation over drinks was going to lead to such interesting data.

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August 2015: The month in review

It’s been a busy blogging month and we’ve all written about challenges and best practices. I found myself advocating that any company that does email marketing really must have a well-defined delivery strategy. Email is such vital part of how most companies communicate with customers and potential customers, and the delivery landscape continues to increase in complexity (see my post on pattern matching for a more abstract look at how people tend to think about filters and getting to the inbox). Successful email marketers are proactive about delivery strategy and are able to respond quickly as issues arise. Stay tuned for more from us on this topic.
I also wrote up some deliverability advice for the DNC, which I think is valuable for anyone looking at how to maintain engagement with a list over time.  It’s also worth thinking about in the context of how to re-engage a list that may have been stagnant for a while. A comment on that post inspired a followup discussion about how delivery decisions get made, and whether an individual person in the process could impact something like an election through these delivery decisions. What do you think?
As we frequently point out, “best practices” in delivery evolve over time, and all too often, companies set up mail programs and never go back to check that things continue to run properly. We talked about how to check your tech, as well as what to monitor during and after a send. Josh wrote about utilizing all of your data across multiple mail streams, which is critical for understanding how you’re engaging with your recipients, as well as the importance of continuous testing to see what content and presentation strategies work best for those recipients.
Speaking of recipients, we wrote a bit about online identity and the implications of unverified email addresses in regards to the Ashley Madison hack and cautioned about false data and what might result from the release of that data.
Steve’s in-depth technical series for August was a two-part look at TXT records — what they are and how to use them — and he explains that the ways people use these, properly and improperly, can have a real impact on your sends.
In spam news, the self-proclaimed Spam King Sanford Wallace is still spamming, despite numerous judgments against him and his most recent guilty plea this month. For anyone else still confused about spam, the FTC answered some questions on the topic. It’s a good intro or refresher to share with colleagues. We also wrote about the impact of botnets on the inbox (TL;DR version: not much. The bulk of the problem for end users continues to be people making poor marketing decisions.) In other fraud news, we wrote about a significant spearphishing case and how DMARC may or may not help companies protect themselves.

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Zombie Apocalypse

I hope my series on zombie addresses has convinced you that there are zombie addresses on your list and that you should be concerned about the effect they have on delivery and metrics. Today I’d like to talk about what you can do to get rid of zombie addresses without affecting too many actual subscribers.
Anti-Zombie Weapons
One thing that many companies struggle with while dealing with zombie addresses is letting go of addresses. They are so tied up in the idea that a bigger list is better that they can’t let them go. Even if a particular address has not had any activity in 18 or 24 months, they insist that they can’t give it up, it might come back and the customer might make a giant purchase. No. It’s a zombie. It’s not coming back, except to eat your brains.
The first step to dealing with zombies is to acknowledge their existence. They are there, they are on your lists and they are dirtying up your lists. Pretending they’re not there does not make them go away. They are zombies. In no case is there a human inside. There is no potential sale lurking, waiting to jump out and act on that perfectly crafted offer.
The second thing to remember is that the humans that used to have the zombie addresses found you once and they are still interested in what you’re offering then they will find you again. They may even already be back on your list with their new email address.
While you can’t identify zombie addresses specifically, you can identify addresses that act like zombie addresses. These are addresses that have no activity over a long period of time, more than 12 months. For these addresses that haven’t had activity in 12 – 18 – 24 months, you want to confirm with the recipient that they are there and want to continue to receive mail from you.
The best way to notify them is to send an email asking if they want to remain on your list. If they fail to act, you will remove them from future mailings. Short, sweet and will let you drop off zombie addresses without much effort on your part.
I know, I know, you aren’t ready to let go so fast. After all, some people have come back after 24 months and made a purchase from the perfect offer. They’re not dead yet! OK. But you can’t get a response from them through email. They just don’t care enough about what you’re sending. That’s when you contact them through another channel.
For instance, if the email address is tied to a web account, say a social networking site or bank account or a web forum, you can also contact the user through your website. Next time they log in, send them a message that says their email address has been removed due to inactivity, but if they want to reactivate they can do so at the subscriber preference center or profile page. When they do, send them an email to confirm that this is the address where they want to receive mail. At this point you can give them a link or a magic cookie to past into the website to verify the address.
Or if you’re a bigger retailer you can send alerts to your customer service staff, so when the account holder contacts you by phone with a question or an order you can get an updated email address. If you have a loyalty program, have an alert come up at the point of sale and the clerk can ask for an updated email address.
I even know one company that would send postcards to their zombie accounts in an effort to re-engage them and get an active email address from them.
If the person never comes back, if they don’t ever interact with your business again, if none of the channels work to contact them and update the address then it really is best to just let the relationship go. It may not be you, or anything you’ve done. People move on, their interests change and that’s part of life. They may have moved outside of your service area, or they may have joined your list for a specific product that they don’t need or you don’t sell. They may have died and turned into a real zombie. In any case, they are not a viable prospect for your mail.
Email addresses and business relationships are not forever. Letting zombie addresses go is important for the health of any email marketing program.

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Zombie email: Part 2

In zombie email: part 1 I talked about how email addresses were tightly tied to internet access in the very early years of the internet. We didn’t have to worry about zombie email addresses because when an account was shut down, or ignored for a long time then mail would start bouncing and a sender could stop sending to that account.
There were two major changes to email accounts in the early 2000’s that led to the rise of zombie emails.
People started decoupling their internet access from their email addresses. Free addresses were easy to get and could be checked from everywhere. No longer did they have to dial in to get email, they could access it from outside the office and outside the home. Mobile devices, including the first generation of smart phones and laptops, helped drive people to use email addresses that they could access from any network. The easy access to free mail accounts and the permanence led people to adopt those addresses as their primary address.
When people changed addresses, for whatever reason, they didn’t have to stop paying. There was no way to tell the free ISPs to stop accepting mail for that address. Free mail providers would let addresses linger for months or years after the user had stopped logging in. Sometimes those addresses would fill up and start bouncing email, but they were not often turned off by the ISPs.
The lack of purging of abandoned addresses was the start of dead addresses accumulating on mailing lists. But there weren’t that many addresses in this state, and eventually they would fill up with mail. When they were full the ISP would stop accepting new mail for that account, and the address would bounce off a mailing list.
Everything changed with the entrance of Gmail onto the scene. When Gmail launched in 2004 they were providing a whole GB of storage for email accounts a totally unheard of storage capacity. Within a year they were providing multiple gigabytes of storage. Other freemail systems followed Gmail’s lead and now all free accounts have nearly unlimited storage. Plus, any mail in the spam folder was purged after a few weeks and bulk mail doesn’t count against the users’ storage quota. Now, an abandoned email account will almost never fill up thus senders can’t use over quota bounces to identify abandoned accounts.
Now we’re stuck in a situation where SMTP replies can’t be used to identify that there is no one home inside a particular email account. Senders can’t distinguish between a quiet subscriber and an abandoned address. ISPs, however, can and are using zombie addresses as a measure of a senders reputation.
On Monday we’ll talk about why and how zombie addresses can affect delivery. (Zombie emails: part 3)
Tuesday, we’ll talk about strategies to protect your list from being taken over by zombies. (Zombie Apocalypse)

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