Recently, some news broke about Yahoo’s increasing reliance on engagement for detecting spam, joining the likes of Gmail, AOL, and Hotmail.

So what’s the big deal here? Previously, email providers relied mostly on content filters to determine whether or not emails were spammy, and it was relatively easy to work within those algorithms to send legit-looking emails. Avoid these specific words, don’t include those bad links, add the required headers, etc. But with the engagement model, email providers are relying less on cold, logical computers and more on emotional, irrational humans.

Consider this the un-Vulcaning of spam filters.

With more and more email providers looking at how their users interact with emails to determine “spaminess,” now is a good time to evaluate what this means for email senders and ways to improve delivery rates.

What Exactly Is Engagement?

Email providers use a few metrics to determine engagement: opens, clicks, unsubscribes, abuse complaints, and just generally treating email like spam or not-spam. For example, if enough recipients click the “send to spam” button on your email, the providers assume that no one else would want that email either. Conversely, subscribers moving an email from spam to inbox would earn some brownie points. Gmail even released a handy whitepaper detailing the relationship of moving emails to or from spam and the effect on engagement rankings. Basically, it’s bad when subscribers move an email to spam; it’s good when they move it out.

Of course, each provider uses its own super-secretive algorithmic-thingamabob, meaning they might prioritize some metrics over others or use different methods of gathering data all together. Common metrics like opens, clicks, replies, and forwards are often figured into an email’s good reputation by all providers. But then there are those who take spam-filtering to a whole new level, a la Hotmail. With their Sender Reputation Data (SRD) program, Hotmail randomly invites users to mark their emails as spam or not. If some of your recipients are in the SRD program, their engagement can carry a greater weight than others. But in the end, the providers are all measuring the same thing: Do people think your email is spam?

So take a holistic view of engagement. It’s not enough to “trick” subscribers into clicking an animated monkey to win a free car if they just unsubscribe a minute later. Your click rate might be phenomenal, but subscribers still treated the email like spam.

It’s important to consider these specific mistakes we’ve seen can hurt engagement:

• Sending email to old or stale contacts, or perhaps even to users who aren’t users
• Uploading everyone who signs up for your application or website, especially Facebook addresses
• Sharing lists between organizations without permission
• Sending email too often or even not often enough, so your audience loses interest or forgets you exist

It’s best practice to stick with permission-based lists and keep your content geared toward the stuff your subscribers expect. If you’re just starting out, take a look at some common mistakes so you can avoid them.

What Happens If My Engagement Is Low?

Nothing apocalyptic, I assure you. But your subscribers might not get your emails, which could be costly. With low engagement, emails are more likely to be sent to the spam folder or throttled to deliver over longer periods of time. We’ve even seen edge cases where email providers just stop delivering low-performing emails entirely.

Here’s the kicker: Low engagement can affect future emails, too. Email providers have gotten pretty good at connecting emails back to the same source. They’ll factor in the sending IP address, the from email address (which is set as the “reply-to address” when creating a MailChimp campaign,) and also email fingerprinting.

Without getting too complex, fingerprinting takes pieces of an email, creates a hash of each piece, and then compares them with other hashes stored in some database to see if the same hash has been received before. So if your emails reuse a design template or even the contact information in the footer, there’s a good chance the email providers can link your past and future emails together.

Of course, this doesn’t mean you should change the from address or make a new template for each campaign. Email providers reward senders with high engagement by increasing the delivery rate and chances emails will go to the inbox. Gmail even prioritizes emails higher in the inbox based on past engagement. Having zero engagement history with the providers just means your emails are more at the mercy of other spam filters, like content, content, and, oh yeah, content.

How Do I Measure Engagement?

You knew this was coming, right? MailChimp does indeed offer tools to help measure campaign engagement. Let’s take a look at some of them now:

Reports

Every campaign includes reports with lots of helpful information about the campaign, the subscribers, and how the subscribers engaged with the campaign. On a basic level, you can see opens, clicks, bounces, unsubscribes, and abuse complaints (subscribers clicking the “send to spam” button in certain email providers, like Hotmail, Yahoo, and AOL). Unsubscribes, bounces, and abuse complaints would be considered negative engagement, while opens and clicks are awesome!

Keep in mind that we only know a subscriber opens a campaign if they click a link or view images (assuming the campaign has tracking enabled, which it will by default.) But the email providers? They know when you are reading, and they know when you’re engaged. Meaning, you can get engagement points for all opens, not just the opens we can track in reports. Hooray! But the providers can also track how long subscribers read a campaign, so not all opens are considered equal. Boo!

Because email tracking isn’t an exact science, we recommend focusing more on trends than specific campaign stats. If you send frequently enough, one email which doesn’t resonate with subscribers won’t destroy your engagement reputation. But if you see opens and clicks declining over time, it’s a pretty good indicator that there’s an engagement problem. Maybe subscribers are losing interest, or perhaps the emails are already being placed in the spam folder more frequently.

You can easily view open and click trends in MailChimp by clicking the Reports tab at the top of the application. There’s a bouncy chart showing opens and clicks for the most recent campaigns, filterable by list, that looks like this:

To view trends of unsubscribes, bounces, and complaints over time, you can export a comparison spreadsheet report.

ListMD

Speaking of report trends, we have a nifty chimplet called ListMD, which provides more thorough data per list. For instance, you can view the average open or click rates per day of the week. So if you find your audience really likes to open emails on Tuesdays…send emails on Tuesdays.

With ListMD, you can also set up custom series based on interest groups, filter activity by date, and export the data to your favorite spreadsheet processor if you’re just a straight numbers kind of person. And while you’re looking around, check out the subscriber attrition rate, which is the average time it takes subscribers to lose interest and stop engaging with emails.

Check it out: We have a whole blog post about all the things you can do with ListMD.

Chimp Chatter

We’re really committed to making engagement visible, so we put it on your Dashboard. As soon as you log in, peruse the overview of new subscribers, lost subscribers, and subscribers so engaged they even updated their profiles. An engaged list should see a good flow of new subscribers and updated profiles, but not so much with the unsubscribes. If you scroll down and only see reports of unsubscribes, there could be an engagement issue. Perhaps you need some fresh blood to make up for the inevitable attrition rate.

Also on the Dashboard, just to the left of Chimp Chatter, we include a recent campaigns widget with the number of opens, clicks, and non-opens. There’s also a List Growth and Top Fives widget, which will show campaigns with the highest opens, clicks, and ROI. Those campaigns might teach you something about what works well for your subscribers.

Great! And Improving My Engagement?

Now we know engagement is important and how to locate engagement issues. So how do we turn the ship around and sail to the inbox together?’

Good List Collection Practices

Let’s start at the beginning, with where subscribers come from. MailChimp provides a few ways to collect subscribers: Double opt-in signup forms, Chimpadeedoo, importing files or address books, and our open API, which is used by many integration developers to create single opt-in signup forms.

I won’t mince words–double opt-in is hands-down the best method of collecting subscribers when it comes to engagement. If you want high open and click rates, low unsubscribe, bounce, and complaint rates, and a high ROI, use double opt-in. We’ve even conducted a study showing double opt-in subscribers will engage significantly more than single opt-in subscribers.

Why is that? Because double opt-in subscribers understand what they signed up for, they want to get it, and they’re actively clicking a link in an introductory email to confirm their subscription. So right away, you know the email address is valid and won’t bounce. Plus the subscriber is willing to engage with emails.

Single opt-in subscribers can still engage, but they tend to less frequently. With single opt-in forms, subscribers usually sign up to receive one particular email, like a coupon, or are signed up automatically while completing an action, likes a shopping cart checkout. They don’t want to receive regular emails, and will bounce, unsubscribe, or send to spam very quickly.

If you’re not using double opt-in now, it’s not too late to switch over. Our hosted and embed forms all use double opt-in, and most API integrations will offer a double opt-in option. If not, contact the integration vendor and send them here.

Prune the List

Let’s say you’ve already got a list in trouble with low engagement. We automatically clean subscribers who bounce, unsubscribe, or complain from lists, but this is after the damage to your reputation has been done. Instead, let’s look at the positive spectrum of engagement: Opens and clicks.

Engagement is a numbers game of percentages. If we send to 10,000 subscribers and only 1,000 open the email, the open rate is 10%. But let’s say we find the subscribers least likely to open emails and prune them from the list? Maybe now we send to 4,000 subscribers and the same 1,000 open the email, which is a much higher 25% open rate. Higher open rates mean more engagement, even if the number of opens is the same. Ah ha!

Consider it’s also cheaper to send 4,000 emails than 10,000 emails to get the same 1,000 opens, and suddenly pruning the list seems like a really good value. Even better, because overall engagement on the email increased, the email is more likely to end up in the inbox and opened by more subscribers.

So it’s entirely possible that sending to fewer people can actually result in more opens. It seems counter-intuitive, which is why so many email marketers focus solely on growing their list. But thanks to engagement filters, you can actually get a better ROI from a leaner, cleaner list of interested subscribers.

Finding unengaged subscribers is a simple matter in MailChimp. To save some space here, check out our handy tutorial on removing unengaged subscribers for step-by-step instructions.

Remember the subscriber attrition rate you got from ListMD? It’s a good idea to prune your list at the same rate. So if subscribers tend to drop off after three months, then prune the list at least every three months to quickly remove those disengaging subscribers.

Reconfirming the List

What if my list is absolute poop, you say? If your list-collection practices are just so atrocious there’s no way to salvage the list, then there’s the reconfirmation option.

Basically, create an empty list and send a personal email to each of your subscribers asking them to sign up for the list again, using the double opt-in form this time. The amount of confirmations will likely seem low, so prepare yourself. But keep in mind that these will be the truly engaged subscribers. The rest are just dead weight costing you money.

We also have a super tutorial on reconfirming your list, but I want to point out that you should send the confirmation email using a personal address outside of MailChimp (or whichever ESP you use for marketing.) The confirmation email is likely to have very low engagement and could damage your reputation for future marketing emails. Personal emails are usually sent to a few familiar contacts, thus less likely to bulk, regardless of reputation.

Oh, Yeah. Content

A good list is vital to good engagement, but people still need a reason to subscribe to, open, and click your emails. Writing good content is a pretty subjective arena, and entire libraries have been written on the topic. Not to put too fine a point on it, I’ll say this: Give your subscribers a reason to read your emails and click things. Every sender will succeed differently, but we do provide some tools to help you find what works best.

A/B split test campaigns are a great way to send two emails with different content or subject lines to small portions of your list. See which one gets better engagement, and then send the winning email to the remainder of the list. Winning factors include opens and clicks, or you can choose the winner manually after viewing other metrics, like unsubscribes and complaints.

Autoresponders are automated emails sent to subscribers based on specific dates, like when a subscriber signs up, makes a purchase, has a birthday, etc. We’ve seen some creative uses of autoresponders, including renewal/reorder reminders, lesson plans, and pregnancy guides. Sending personalized emails to subscribers keeps them from unsubscribing or sending emails to spam, especially if subscribers expect them.

We also have a barrel of chimplets and integrations to help send customized content to subscribers based on their personal interests and actions:

• Goooal segments lists based on which of your web pages subscribers visit.
• Ecommerce360 segments subscribers based on their purchases and order dates.
• ChimpMap can send a chain of campaigns based on subscriber engagement, like opens and clicks.

Segments can be used with smart merge tags to deliver personalized content to each subscriber, making it easier to maintain high levels of engagement and even beat back that attrition rate.

At the End of the Tour

You’ve lasted this long, so I’ll wrap it up quickly. Engagement, at its basic level, is just keeping senders honest. No tricks, no trying to get around computer programs. Just good ol’ fashioned best practices for list collection and content writing. Give the people what they want, and only the people who’ve asked for it. (Asked for it twice, just to be certain.)

 

Also See:

• Major Email Provider Trends in 2012: Gmail Pulls Ahead 
• This Just In: Subject Line Length Means Absolutely Nothing
• Daily Senders and Deliverability
• Study: Are Daily Deals Dead?