Email marketing offers eCommerce stores a number of tantalizing perks. First and foremost, the return on investment is undeniable; studies have shown that every $1 spent generates a return of $37 or more. Additionally, email marketing remains the most direct and unobstructed digital marketing platform; unlike social media, there are no capricious algorithms standing between your message and your subscribers. As an added bonus, your emails are highly customizable to suit your unique brand and voice.
But, in order to realize all of these potential benefits, you need to successfully reach your customers. Turning a strong pitch into sales begins with open rates.
Simply put: if your customers aren’t opening your emails, they aren’t engaging with your content. One stark reality of email marketing is that an average eCommerce email remains unopened by nearly 85 percent of customers.
The purpose of this guide is to demystify the sneakily complex subject of open rates and provide strategic tips to help you improve your results. This guide will also explore a few common pitfalls that might be holding you back from achieving strong open rates.
Calculating open rates
Email open rates inform several other crucial analytics in a number of ways, but calculating open rates is quite simple. Here’s the most basic formula used by email marketing platforms:
Open Rate = Number of emails opened / Number of emails sent
A more accurate formula would factor in the number of bounced emails by subtracting them from the number of emails sent. The resulting percentage gives you the open rate among customers who actually received your email.
Open Rate = Number of emails opened / (Number of emails sent – bounces)
Most email platforms do this math for you, providing open rates along with other key analytics, like click-through and unsubscribe rates. As further discussed throughout this article, your open rate is an indicator of more than just the success of an individual campaign’s subject line. Chronically low open rates can be an indicator that your email list includes a high number of inactive subscribers, or a tendency for your emails to get caught by spam filters—or both.
Establishing your open rate benchmark
Industry average open rates for eCommerce stores are fairly low, with one study placing the average at just 16.75 percent. It’s best to view this as the floor; your goal is to do everything you can to exceed it.
However, your subscriber base is unique, and that’s why we recommend establishing your own benchmark as a first step in improving your open rates. Your email marketing platform should keep a record of your analytics over time. Start by setting a date range and reviewing your open rates over that time period. Note your average for that time span, and also pay attention to how your open rates fluctuate depending on how you’re employing list segmentation strategies. If you’re sending every marketing email to your entire list, instead of sending targeted emails to specific segments, you may have discovered the root of your problem.
Additionally, note how your open rates vary based on the type of email you’re sending. Transactional emails like receipts and welcome emails will often achieve higher open rates than general sales emails. The goal is to monitor how each type of email performs so you can work toward meaningful improvements in each area.
Once you’ve established your own open rate benchmark, you can use it as a reference point as you start to initiate improvements. If your starting point is around 21 percent, you’re already above average for eCommerce stores. That said, you still have plenty of room for improvement; studies indicate that a good open rate for businesses is 32 to 35 percent.
What’s holding back your open rate?
If you’re struggling to meet or exceed industry average open rates, there may be a number of issues with your email list and marketing strategy. Here are a few of the most common issues and the damage they may be causing to your open rates:
Lack of list segmentation strategy
It’s unrealistic to expect that every one of your email subscribers is interested in every single thing you’re promoting. That’s where segmentation comes in. You can use segmentation rules based around things like past purchasing behavior and customer demographics to send targeted, relevant emails to different groups. One study found segmented email campaigns see 14.37 percent higher open rates than unsegmented campaigns—a strong indication that a little extra targeting effort goes a long way.
Let’s say, for example, your store sells old-timey beach hats, and your data shows that they’re especially popular with people living in Brooklyn and Portland. Not surprising. By using segmentation rules, you can target that group specifically with special deals on old-timey beach hats—likely generating higher engagement rates than if you’d simply emailed your entire list. As an added bonus, you’ll make your hipster customers feel like you’re truly paying attention to their needs.
Without this type of targeting strategy, you run the risk of sending messages that feel irrelevant to some of your customers, and that may result in a sense that you’re not paying attention to what they want. If your content feels irrelevant, your subscribers are likely to stop opening your emails and eventually unsubscribe—or worse, begin marking your emails as spam.
Inactive subscribers
A low open rate isn’t solely traceable to the quality of your email content. Life events and shifting interests among your customers also play a role as time passes. One study found that email marketing email lists decay at a rate of 22.5 percent per year; in other words, almost a quarter of your list may become inactive within the span of just one year. If you haven’t performed routine list maintenance in a while, your email list is increasingly susceptible to being overrun by inactive subscribers.
Here are just a few reasons why email addresses become inactive:
- An email provider becomes obsolete or goes out of business, forcing users to switch accounts.
- The subscriber switches jobs and acquires a new work email address.
- A user stops logging into an email account, resulting in the provider deactivating their address.
- The subscriber simply loses interest in a company and stops opening their emails.
Over time, an ever-increasing number of inactive subscribers will lead to higher bounce rates and lower deliverability. These factors can hurt your reputation of the sender, resulting in a greater chance that future emails will be filtered into spam. Routine list cleaning can help avoid this unfortunate spiral and keep your list healthy for the long haul.
Subscribers who never opted in
On a related note, acquiring subscribers without giving them the opportunity to opt in can further increase your rate of email list decay. In fact, these unwitting subscribers are more likely to feel annoyed and resentful toward your communications, increasing the likelihood that they will mark your content as spam. Over time, this will hurt your sender reputation and contribute to lower deliverability, which further lowers your open rates.
It may feel daunting that a seemingly simple metric like open rate can be impacted by such a wide variety of factors, many of which feel outside of your control. The good news is that problems with your open rates are fairly easy to diagnose and treat.
Improve the content of your subject lines (and emails)
Subject lines serve as a gateway to your email content, and the success of your subject line is predictive of higher open rates. In fact, one study found around half of subscribers will open an email based on the subject line alone.
Here are a few top strategies you can employ to boost your chances of subject line success.
Be clear and direct
If you’re at all unsure about your ability to write effective subject lines, take comfort in knowing that your best bet is a simple, straightforward subject line that is clearly representative of its accompanying email content. In fact, one study found that clear and direct subject lines performed 366 percent better than “cute and clever” subject lines.
A reasonable first step in crafting a clear and direct subject line is to describe the email contents in a few words. For example, if you’re launching a new line of travel accessories, you can start out with “The Excelsior Travel Line Launches Today!” From there, put some thought into details that would make this even more enticing for your customers. Are you offering an early-bird discount, or a special deal for repeat customers? Work that into your subject line, like so: “Save 33% on our new Excelsior Travel Line!” Studies have shown that highlighting a discount in a subject line can provide a boost in open rates.
Don’t mistake being clear and direct with being totally dry and boring, though. This email from Italic demonstrates the power of a straightforward subject line, with the added touch of framing their announcement as a PSA. That small touch adds just enough charm to the subject line to keep it from feeling too generic—while still keeping it clear and direct.

Evoke curiosity
While clear and direct subject lines certainly have their place, there’s also power in piquing curiosity. The strategic use of curiosity words taps into our natural urge to learn more; words like astonishing, confidential, elusive, insider, priceless, and unique can push your subscribers to click to learn more.
This email from ace&jig uses a curiosity-building subject line (“what’s coming this friday”) to get their fans to open—if you’re a fan of the brand and their new products, you’re going to want to find out what is coming this Friday. (Spoiler alert: It was their new fall styles.)
The key with curiosity is to not overdo it—in fact, it’s ideal to anchor your attempt with some degree of clarity about the enclosed content. Your customers subscribe to your email list because they’re interested in your products and want to stay in the loop. While some intrigue can be effective, it’s best not to play it so coy that you end up confusing, annoying, or misleading people.
Convey urgency and tap into FOMO
FOMO stands for fear of missing out, and this simple facet of human psychology is frequently utilized to drive engagement. One study found that subject lines that effectively convey urgency perform better on the whole than those that don’t—as long as you don’t stray too far into clickbait territory. Words and phrases like “shocking” and “you won’t believe” may prompt a sense of urgency, but years of use in clickbait-style emails and articles has made these tricks much less effective and may hurt your open rates. Instead, use words that convey immediacy in a more positive and affirming fashion; today, urgent, important, and alert are all solid choices.
In this email from TOMS, they use the subject line “The shoe everybody loves”—implying that if you don’t open the email, check out the shoe, and possibly even buy the shoe, you’re going to be left out among the throngs of shoe lovers who are clamoring for their pair. It’s an effective subject line that creates a sense of FOMO without treading into the world of clickbait.
For even more advice, check out our blog post on writing great subject lines.
Personalize to send relevant content
Personalized content is far more effective than non-personalized; and when it comes to open rates, emails with personalized subject lines are 26 percent more likely to be opened.
Fair warning: there’s more to personalization than putting someone’s name in the subject line. In fact, that might backfire—one study found people reacted negatively to seeing their name, as it made the email feel invasive and creepy. Personalization isn’t about showing off how much you know about a customer—it’s about crafting an email that serves them, and them specifically.
Here are some personalized types of emails that your customers will want to open:
- Happy birthday emails, or emails on the anniversary of the customer’s first purchase.
- Updates on VIP and loyalty rewards status.
- Recommended products based on purchase history.
- Guides for a product they purchased.
- Follow-ups on a purchase to check in on how they like it, offer support, and ask for a review.
There’s plenty of motivation to take this extra step with your marketing emails—studies have found that personalized emails based on past behaviors have 25 percent higher open rates and 51 percent higher unique click rates.
Don’t neglect your preview text
Preview text is an optional feature provided by most email platforms. It provides an opportunity for accompanying text to show up next to your subject line in customer inboxes. The beauty of preview text is that you can take creative risks that might not always be advisable for subject lines. For example, you can play it safe with a clear and direct subject line while using preview text to evoke curiosity:
Subject Line: Save 33% on our new Excelsior Travel Line!
Preview Text: How far will these exclusive deals take you?
You can also take your combination in the opposite direction by using a funny or clever subject line, then laying out specifics and details in the preview text. Either way, when used effectively, your subject line and preview text can serve as a dynamic duo to boost your email open rates. In fact, one study observed a 7.96 percent lift in open rates when preview text is used effectively.
Check out these emails from the home design brand Rejuvenation. Sometimes they put the marketing hook in the subject and nuts and bolts of the offer in the preview text—sometimes it’s vice versa. By switching it up, they keep their emails fresh and they’re able to deliver a message in the inbox that’s both intriguing and direct.
Optimize your emails
Focus on mobile
Studies have found that two-thirds of emails are opened on mobile devices—so it’s crucial to take screen size into account when you’re crafting subject lines. For complete visibility on most modern devices, the ideal subject line length is 35 characters or less.
While optimizing your subject lines for mobile screens is important, it’s just one step in ensuring your content is successful in mobile formats. Reduced screen size impacts other aspects of email content, including legibility of text, how images are displayed, and how much of your from field and preview text is visible. Additionally, email habits among mobile users are distinct from those who primarily use their desktop computer to read emails; for example, mobile users are more likely to check their email first thing in the morning and late at night.
In general, when it comes to mobile, smaller and shorter is better.
- Again, aim for subject lines that are 35 characters or less.
- Front-load your preview text so that the most important information appears within the first few words of your copy.
- Stick with one column for your content and remember that screen widths vary widely across mobile devices. Generally, content width between 450 to 600 pixels will work with most screens.
- Place your primary call-to-action and the most important supporting information as close to the top as possible.
- Be mindful that an overly complex email layout may not translate to a mobile screen, even if it looks fantastic on your desktop.
- One exception to the “smaller and shorter is better” maxim: keep the text large. You’ll want to set your email body copy at a minimum of 16 pixels to ensure legibility across all mobile devices.
The bottom line is that if you don’t optimize your emails for mobile, your subscribers who use mobile as their primary device for checking email will be unsatisfied with your content and more likely to stop reading it.
Improve your timing
The ideal scenario is that your marketing emails will arrive in customer inboxes right as customers are ready to read them. The challenge is that everyone is different, and personal preferences play a large role in how and when emails are opened and read. On top of that, it’s likely your subscribers are spread out in multiple time zones. As a result, there is no definitive best time to send a marketing email. The best you can do is observe the available research and take into consideration any demographic factors that make your core customers unique.
One extensive study identified a few trends in email send times:
- Mid-week appears to be the best time to send emails, with highest open and click-through rates occurring on Thursdays.
- In contrast, sending emails on Saturdays and Sundays appears to generate the least success with open and click-through rates.
- Across all tested industries, including retail, the best time of day to send email is between 8 AM and 10 AM.
- These results remained largely the same across several demographic indicators, including age, geographic location, and profession.
While the results of this test are fairly encouraging toward marketers who concentrate their email send times during midweek mornings, the reality is that your brand may achieve better results at different times. Your best bet is to figure out the find the time of day that yields the best results for your brand. And that’s where A/B testing comes in.
Use A/B testing to your advantage
One study found that subject lines are the most frequently tested email element, followed by the message body itself, layout, and images. Email marketers can use A/B testing to try out new strategies and compare how certain types of subject lines perform against others.
For example, you may want to get a sense of how a direct, straightforward subject line will fare when matched against a subject line that is designed to evoke curiosity. Alternately, you may want to test how a more aggressive, impersonal sales pitch matches up against email content that’s more casual or personalized. Either way, you can send each version of your email to a small segment of your list. You’ll want to give your test at least 48 hours to generate meaningful results (the smaller your list segments, the longer it will take); you can utilize an online calculator to determine if your results are statistically significant.
Maintain a clean, healthy email list
Regularly purge inactive and disengaged subscribers
As previously discussed, large numbers of inactive subscribers can do serious damage to the quality of your email list. While it’s understandable for any brand to prioritize and pursue email list growth, commitment to routine email list hygiene will ensure that you’re sending marketing emails to customers who want to receive them. The corresponding improvements in open rates and engagement with content should keep your reputation high and help you avoid spam filters.
There are several indicators that may point to the need for email list cleanup:
- Decreasing open rates. If you notice that your open rates continue to drop, it’s likely that your list contains an increasing number of inactive and disengaged subscribers. By removing them, you’ll effectively increase the overall share of engaged subscribers on your list, likely facilitating higher open rates over time.
- Increasing unsubscribe rates. Unsubscribing is a customer’s most direct option for informing you that they no longer wish to receive your marketing emails. Normal unsubscribe rates range between 0.2 and 0.5 percent per email sent. If you notice that your unsubscribe rates are rising above 0.5 percent per email sent, it’s time to prioritize cleanup of your email list.
- Higher bounce rates. Emails bounce when they reach an invalid or inactive email address, or an addressee that has already marked your communications as spam. A higher bounce rate can hurt your email deliverability, making you even more susceptible to spam filters. A routine email list cleanup can help you avoid this cycle and reach a higher percentage of inboxes that are receptive to your communications.
- More frequent spam complaints. While many customers who don’t wish to receive your emails will opt to unsubscribe, some will fully take you to task and mark your emails as spam. You’re more susceptible to spam complaints if you don’t provide an easily locatable unsubscribe link or button in your marketing emails. Ultimately, it’s better to have unengaged subscribers choose to unsubscribe than to suffer the damage to deliverability that occurs when you’re marked as spam. It’s also worth noting that in the United States and many other jurisdictions, providing a way to opt-out is required by law. That said, these regulations don’t apply to transactional emails like receipts and shipping notifications; in some cases, your legal responsibility to provide pertinent information about the transaction precludes you from providing a way for the recipient to opt out of receiving that information. For more on this topic, see our helpful resource on privacy, PECR, and the GDPR.
- Poor deliverability. All the above indicators can result in damage to your email deliverability. Ideally, you want to maintain a deliverability rate above 90 percent to keep your list healthy. If you notice your deliverability rate slipping below that threshold, it’s best to expedite email list cleanup to purge inactive and unreceptive subscribers to solve the problem.
For a complete run-down on best practices for email list cleanup, be sure to check out Jilt’s article on email list hygiene.
Use win-back campaigns
Before you dive headlong into email list cleanup, you may want to consider conducting a win-back campaign. Simply put, a win-back campaign targets customers who haven’t engaged with your content or made a purchase over a significant stretch of time. Your preferred time interval will depend on several factors that are unique to your business. What’s normal for your customers in terms of purchase frequency? How long are your products expected to last? Do you experience seasonal ups and downs based on the nature of your products?
Once you’ve established your win-back criteria, it’s time to put together your automated win-back email or series. Phrases like we miss you, it’s been a while, and hoping to reconnect soon will project a sense of caring about the customer that may facilitate a rejuvenated interest in your products. And if a subscriber still doesn’t re-engage after your win-back email, then it’s time to purge them from your list.
Here’s an example of a win-back email from Lands’ End. It isn’t angry or accusatory—it just lets the customer know it’s been some time since their last purchase and showcases both a deal and all the stuff the person is missing out on by disengaging from the brand.

Avoid spam filters
Your subscribers can’t open your emails if they never see them—and that scenario can happen if your emails bypass subscribers’ inboxes and go directly to spam. Many of the recommendations contained in this guide are fine-tuned to help you avoid spam filters. Here are a few more tips to keep your deliverability rates healthy:
- Avoid spam trigger words. If a word or phrase feels spammy to you, it’ll feel that way to your customers too—and it’s also likely to trigger automatic spam filters. Thus, it’s best to avoid common trigger words and phrases like cheap, click here, $$$, incredible deal, and order now.
- Avoid ALL CAPS in subject lines. There are more effective ways to convey urgency than resorting to all caps. All caps subject lines are 30 percent less likely to receive a response than all other subject lines.
- Don’t use bait-and-switch. If directness and clarity are your best bet for subject line success, being tricky or misleading might be the worst. It may be tempting to employ some misdirection in an attempt to evoke curiosity. The issue arises when your customer clicks through and finds that the email’s content is drastically different from what they were expecting. This can cultivate a feeling that the customer shouldn’t trust you, particularly given that bait-and-switch advertising is often employed in scams.
Open rates are a uniquely important indicator of email marketing success. Lagging open rates can impact other key performance indicators, including click-through rates and conversions. Your subscribers simply won’t get far enough to answer your calls-to-action if they aren’t motivated to open your emails.
If you’re struggling to exceed industry average open rates for eCommerce stores (16.75 percent, according to one study), your first job is to figure out why.
- Your benchmark is unique. Industry-wide open rate benchmarks are helpful for assessing where you stack up against your competition, but establishing your own benchmark may be more useful toward making improvements. Use available analytics provided by your email marketing platform to assess your unique average open rate and to establish reasonable improvement goals.
- Diagnose the problem. Several factors may be hurting your open rates, including a lack of email list segmentation strategy, growing numbers of inactive and disengaged subscribers, and a prolonged period of time between email list cleanups. Quality of email content may also play a role. You can use your available analytics to figure out where breakdowns are happening.
Whether your open rates are low or they’re pretty high but you want them to be higher, there are a number of strategies you can use to get a boost.
- Improve your open rates by improving your subject lines. Use proven strategies for subject lines, like being clear and direct, or evoking curiosity or urgency. And don’t neglect your preview text—it adds an extra dimension to your subject line and can aide in the process of compelling subscribers to open your marketing emails
- Optimize for mobile. 67 percent of users open their email on mobile devices.
- Use personalization. There’s much more to personalization than using first name merge tags; perhaps the most impactful way to personalize email is to utilize proper list segmentation and ensure that subscribers are receiving content that’s relevant to their interests and past behaviors.
- Time your sends correctly. Effective timing also plays a role in email rates, though what works for one brand may not necessarily work for another. And that’s why you’ll want to use A/B testing…
- Employ A/B testing. You can test your subject line style, delivery timing, and content voice to get valuable insights into what works for specific segments of your email list.
Open rates are also linked to list hygiene—if your list is filled with people who aren’t engaging with your brand anymore, that’s going to affect your opens.
- Perform regular list maintenance. Proper email list hygiene and regular cleanups can solve for many common email list problems, including high numbers of inactive subscribers, high bounce and unsubscribe rates, frequent spam complaints, and poor deliverability.
- Use win-back campaigns. A win-back campaign should be performed before list cleanup to ensure that interested customers aren’t included in a major purge of subscribers.
- Avoid falling into spam folders. Steer clear of spam filters by avoiding spam trigger words and all-caps formatting in subject lines, and avoiding scammy tactics like bait-and-switch marketing.