Advanced methods to measure email acquisition strategy

Trendline Interactive

5 minute read

Your email marketing program relies on many factors for success, but the most important is the quality of your email database. In earlier blog posts we’ve reviewed strategies for acquiring more of the high-quality email addresses that will grow your email program and help you achieve your business goals, and for measuring the success of those strategies. Now we’ll look at some specific metrics that will help you refine your success measurements when it comes to a good email acquisition strategy.

Pay attention to these early-warning metrics

Opens, clicks and conversions are reliable ways to measure how active and interested your email subscribers are, but they are long-term indicators. Their greatest value comes when you track them to see if they’re trending up or down.

Two metrics need  your immediate action, both to correct as soon as they occur and to serve as the springboard for investigation into potential problems with acquisition sources. They also indicate low-quality subscribers but have more power to damage your email program than people who simply ignore your emails.

1. Hard bounces

A hard bounce occurs when you try to deliver an email to an address that doesn’t exist or doesn’t accept email. A soft bounce, on the other hand, is a temporary inability to deliver to an email address. Soft bounces usually resolve themselves, while hard bounces are permanent.

An undeliverable address might have typos or is missing the “@” symbol or top-level domain like “.com.” Or it belongs to a closed or fake email account. A regular program of list hygiene can help you remove undeliverables and keep fake ones out at opt-in, but even legitimate addresses go bad over time.

In the short run, you must remove hard-bouncing email addresses immediately. If you don’t, they could hurt your sender reputation. That causes deliverability problems and can get you locked out of key ISPs.

But you also need to look at the percentage of hard bounces your email campaigns generate and where those addresses come from. If you can tie a high rate of hard-bouncing emails back to a specific acquisition source, you can turn it off until you figure out what’s going on. Then use hygiene practices to find and remove these bad actors before they cause permanent damage.

If you see high hard-bouncing rates across a wide range of acquisition sources, including your own opt-in pages, this indicates you have a more serious problem – you’re allowing undeliverable addresses into your database without detection. Conduct a deliverability audit to figure out what’s really going on. It could be more serious than you think.

2. Spam complaints

Like hard bounces, spam complaints need to be dealt with immediately because they pose an immediate danger to your sender reputation and ability to deliver email, even to legitimate addresses.

Spam complaints are generated by people who mark your emails as spam or junk. These are deliberate actions that indicate dissatisfaction. They might not actually be saying they think you’re spamming them, though.

Instead, people sometimes click the “report spam” button because they think it will stop your email from coming or because it’s easier than looking for your unsubscribe process. (Or they don’t trust your unsubscribe process, which is a whole different topic).

The point here is that ISPs don’t care why someone complained about your email – only that they did click the spam button. If you generate too many spam complaints, you’ll get blocked from that ISP.

As with hard-bouncing email addresses, you must remove them immediately and not send to them again. Then, track complaints over time to see if they’re trending up or down and look at your acquisition sources to see if some are more likely to send you more spam-complainers. That probably indicates they’re not following permission guidelines. Either way, these subscribers are not going to help you grow your email program.

Sending to those who don’t want your content is a surefire way to damage your reputation.  You could end up on a blacklist, which would be the worst-case scenario for your marketing program.

5 metrics that measure list quality and performance

We’ve previously covered engagement and customer activity metrics that help you judge the value different kinds of subscribers represent for your email marketing program and your business. The final set of metrics brings out hidden cost, conversion and revenue aspects that activity metrics like opens, clicks and conversions or even lifetime value don’t reveal:

Cost per conversion (CPC): This could either be at the landing page level or a longer term KPI that can include conversion to a sale or a piece of content. This metric is effective once you know what sources convert at the highest levels and cost you the least.

Cost per engaged subscriber (CPES): First, define engagement over both the short and long term. Then, understand what your spend-to-engagement would be.

Revenue per source (RPS): Here you figure out which acquisition sources are most likely to deliver the customers that contribute directly to revenue. Knowing which sources are most profitable over time will help you focus your time and budget accurately.

Conversion by channel (CBC): B2C marketers use many channels to acquire subscribers, such as  social, site activities, search, localized marketing, co-registration and email append. Know which channels lead to the highest conversions or revenue. This also makes you more efficient with time and budget.

Average conversion time by channel/vendor (ACBC): Which channel or vendor/partner converts the quickest/ slowest? This can help you decide where to allocate more budget.

Compare new subscribers to your base

Context is everything when you need to improve your subscriber acquisition. Know how your new customers compare to your active subscriber base in both immediate and long-term engagement and in cost and revenue metrics.

Your newest subscribers are likely to be more active. If not, or if you don’t see much difference in opens and clicks, you probably need to work harder to engage them right away or risk losing them to inactivity, unsubscribing or even spam complaints.

They might not be your highest revenue-generators, though, but that doesn’t indicate that they’re lower-quality subscribers. But new subscribers who don’t generate revenue will need more persuasion. Tracking them by acquisition source can help you identify problems with the way you express your value proposition or manage expectations.

Wrapping up: Email is a continual numbers game

With everything you have to do to create and maintain a successful email marketing program, it’s not surprising that you can overlook trends in key areas like acquisition effectiveness and subscriber quality.

That’s why you must dedicate time to tracking and crunching numbers. Tying your investigations to acquisition sources is essential because it can help you identify which sources are most likely to send you the highest-quality subscribers that you can count on to help you run an email marketing program that delivers measurable and consistent results and achieves your goals.

The chart below highlights the effectiveness of each acquisition source. By segmenting the audience by source you can see at a glance which source brings in that higher engaged customer based on the stats selected and how each source segment compares to an average benchmark.

Email Acquisition Source Analysis
Acquisition source analysis: This is a simple yet powerful data visualization report that helps you understand how effective your email acquisition sources are at bringing in engaged subscribers.

But it’s a big challenge, especially if you are a lean marketing team. An outside expert like Trendline Interactive can assess your acquisition strategy and effectiveness, review your sources and suggest new ones and show you how to track results accurately.

Want to brainstorm some ideas? We’d love to help!

Review the two earlier entries in our acquisition series:
“How to Grow Your Email Marketing List”
Measure your email acquisition success

Trendline Interactive

Ready to send better messages?

About the Author(s)

Trendline Interactive

Built from email marketing, Trendline Interactive is an agency and consultancy that inspires brands to create meaningful engagement through cross-channel communications. Our passion is that every single message sent is not only meaningful to the audience, but drives success for our clients.

Let's Take This to the Inbox

Sign up for our news, resources and updates. The inbox is our favorite place after all. We’ll make sure it’s worth it. (You can unsubscribe at any time, but you probably already knew that.)