6 Smart Fixes That Reduce Data Decay and Boost Email Marketing ROI

Marketing budgets are tight, and every dollar needs to work harder than ever. That means sticking with high-ROI channels like email—but there’s a catch. Your email list may not be as accurate as you think.

New research shows that B2B email lists decay at 28% per year—faster than ever before. (Think about it: nearly a third of your carefully-built list could be outdated in just 12 months!) Layoffs, job changes, company closures, and mergers all contribute to the churn. And if you’re not actively maintaining your data, you’re likely wasting time and money on emails that will never reach the right people.

So, what should B2B marketers be doing right now? Here are six key moves to keep your email list clean, your campaigns effective, and your ROI strong.

1. Take a Hard Look at Your List

Not all industries and businesses are affected equally by turnover and email decay. Some are seeing rapid changes, while others remain relatively stable. If you haven’t already, take a fresh look at your target audience. Which sectors are experiencing the most volatility? Are key accounts shifting? Does your ideal customer profile (ICP) need updating? (Check out our recent blog on modernizing your ICP to improve campaign results).

Understanding how external shifts impact your audience will help you fine-tune your list and messaging.

2. Track the Right Numbers

A sudden dip in your email engagement isn’t just a sign of a weak subject line—it could be data decay at work. Pay close attention to:

• Hard bounce rates – These indicate invalid email addresses. If they’re climbing, your list needs attention.
• Open and click-through rates – If they’re steadily dropping, it could mean more of your emails are landing in inactive inboxes.
• Reply rates – If previously engaged contacts have gone silent, they may no longer be there.

These metrics will tell you if data decay is impacting your marketing, and where to focus your cleanup efforts.

3. Don’t Ignore the Cost of Bad Data

Outdated email addresses aren’t just an inconvenience—they’re costly. Every email to a dead address is wasted marketing spend. Worse, sending too many emails to invalid addresses can damage your sender reputation, leading to lower deliverability across the board. If ESPs (email service providers) see you as a risky sender, even your best, most engaged contacts may stop receiving your emails.

4. Get Serious About Data Cleansing

Manually updating your database is time-consuming, and for large lists, nearly impossible to keep up with. And even if you do a one-time cleanup, the decay never stops. That’s why ongoing data cleansing is essential.

Using automated tools or a professional database cleansing service streamlines and strengthens your processes for removing outdated contacts, error correction, and replacing invalid addresses—keeping your list as fresh as possible. At OMI, we use data cleansing to maintain the quality of our own massive business contact database and offer it as a service for our clients’ databases to increase deliverability and engagement.

In one case, for a leading telecom provider with 35 million records, data cleansing improved their email validity and accuracy by 37%. For ongoing accuracy, look for a service that also provides a cleansing maintenance program to continuously optimize data accuracy and validity.

Want to maintain accuracy long-term? A monthly data maintenance program is the way to go.

5. Replace Lost Contacts with New, High-Quality Data

If a big chunk of your list is outdated, you don’t just need to clean it—you need to replace lost contacts. That’s where acquisition email data comes in.

Instead of relying only on inbound leads (which take time to build), acquisition data allows you to proactively find and reach new contacts who match your buyer personas. Just make sure you’re sourcing data from a reputable provider that guarantees accuracy. (At OMI, for example, we offer 95% email validity for 30 days, which is well above industry standards.)

We use our Living File® B2B database—consisting of 145 million+ manager-, director-, and professional-level and above contacts with email/HEM, social URL, and other attributes—to perform custom audience building for clients. These audiences can be used for media activation, email acquisition marketing, CTV, programmatic, social, and other omni-channel campaigns.

6. Build More Robust Data Records to Improve Personalization

Today, as B2B and B2C personas are converging,  we are seeing the emergence of "B2B2C" data to unlock the personal and professional attributes of your prospects, enabling improved campaign targeting, personalization, and relevance. In step with this movement, it’s becoming clear that those marketers who adopt new techniques, channels, and data sets to activate audience reach to decision-makers—both at work and home—are successfully turning more prospects into customers.

OMI is addressing this shift with our colossal B2B2C database and B2B2C linkage service, which provide our clients with a more robust personal-professional profile of each prospect they target. We combine B2B attributes such as email, firmographics, and job title with B2C attributes like the prospect's LinkedIn profile, demographics, and residential address.

How it works: Our service spans 145 million business contact records with residential/consumer linkage on 90 million of those records, which is exceptional in the marketing industry.

We match our data records to Trade Desk and the top social platforms, with up to 15 total platforms available for matching. Our aim is to provide our clients with custom, highly-targeted audiences made up of comprehensive prospect profiles that can be leveraged to elevate digital advertising personalization, relevance, and ultimately, campaign ROI across omni-channel points, including direct mail, email, social, and programmatic.

Here's a quick example of how B2B2C data linkage works: A marketer can send direct mail to a B2B contact’s home address while also engaging with them on their business email using the same offer to reinforce the message.

The Bottom Line

With email lists decaying faster than ever, B2B marketers need to be proactive. If you’re still relying on the same old list without maintaining, updating, and modernizing it, you’re losing potential leads—and hurting your deliverability.

The fix? Regularly clean your data, replace lost contacts, and keep a close eye on engagement metrics. A data-driven, proactive approach that embraces new data strategies like B2B2C will help you get the most out of your email marketing efforts and keep your pipeline full.

Please reach out to our team at request@outwardmedia.com for a no-cost marketing data consultation. Go here to read our white papers and case studies to find out about how we power marketing success with data.