• by Jack Loechner , Staff Writer @mp_research, July 8, 2015

According to a study and analysis by Return Path, from subscriber engagement with 199 million messages in 600,000 mailboxes, Email send frequency requires a delicate balance: send too little and leave money on the table, too many and customers become annoyed leading to complaints, list churn, and deliverability issues.

But the problem is there is no one-size-fits-all strategy when it comes to frequency, says the report. If the right frequency really is non-existent, should you just pick a number and hope for the best, asks the report? The study explores the effects of both under and overmailing, to show how tipping the balance in either direction can undermine the effectiveness of an email program.

Conventional wisdom points to decreasing send frequency as the “safe” approach. Fewer emails should result less frustration from subscribers, and therefore fewer complaints. But there are plenty of problems associated with undermailing, says the report:

• Missed Revenue Opportunities:  The most obvious pitfall of undermailing is that potential customers can’t buy from you if they don’t know about your products. By limiting your email sends, the chance of catching a subscriber in a buying mood decreases.
• Lower Lifetime Value  Without timely, relevant content, subscribers may not find it worthwhile to continue their relationship with your brand. The fewer emails sent, the fewer opportunities to prove the value of the email program.
• Increased Complaint Rate  With fewer total sends, each complaint has a greaterimpact on the complaint rate. 4,000 emails may receive 100 complaints, or 2.5%. If you decrease sends to 2,000 and see complaints drop to 75, the complaint rate increases to 3.75%.
• Lack Of Inbox Presence  The average subscriber receives more than six emails each day, 53% of which are promotional.If emails are too few, subscribers may not recognize your brand. Sending too little will decrease your impressions and hurt overall inbox mindshare.
• Poor Or Inconsistent Sender Reputation  Infrequent senders may have difficulty building and maintaining sender reputation, because sender reputation metrics only track 30 days worth of sending history. IP addresses without a consistent sending history will likely have their emails blocked by provider.
• Inability To Maintain A Clean List And Avoid Spam Traps  Sending infrequently will make it difficult to identify abandoned email addresses in a timely manner. Abandoned email addresses can be recycled into spam traps in as little as 30 days, so the less often you send, the more likely you are to hit a spam trap.  

The consequences of overmailing are better understood than those of undermailing, but they’re no less critical to your email program, says the report:

• Decreased Engagement  The most likely action is no action, recipients will simply start ignoring your email, leading to a less engaged subscriber list.
• Increased Opt-Outs  Disgruntled subscribers may go a step beyond ignoring your emails and actually unsubscribe from your email program, leaving lost potential revenue opportunities and a bad customer experience.
• More Total Complaints  Higher send volume may not lead to an increased complaint rate, but, significantly, total number of complaints, as well.
• Reduced Visibility For All Subscribers  As complaints and unsubscribes increase, sender reputation and inbox placement are likely to suffer. Mailbox providers may filter or block incoming messages. With less email landing in the inbox, the brand will experience limited exposure, missed revenue opportunities, and lower lifetime value.

Most marketers use engagement level as a basis for making decisions around send frequency. Best practices typically recommend sending more to engaged subscribers, as they’re less likely to complain, and sending less to disengaged subscribers because they tend to complain more, causing deliverability issues. In fact, the research found the exact opposite to be true, says the report.

By segregating subscribers based on how they interact with email as a whole, you will be better equipped to judge their overall email frequency tolerance. For the study, subscribers were grouped into three categories based on the panel:

• Primary: These accounts are actively engaged, meaning subscribers regularly show inbox activity like reading, deleting, and moving messages. Email sent to these accounts are read and interacted with, accounting for 83% of all reads, but it also draws a surprising number of complaints. Primary inboxes account for roughly 24% of users among our panel, but generated 50% of all complaints.
• Secondary: These accounts receive a high number of promotional and transactional messages, but few personal messages; subscribers are less engaged than Primary accounts. Secondary accounts are moderately active, reading only a small percentage of email they receive. These accounts make up 67% of all users in the panel, accounting for just 16% of total reads and approximately half of complaints.
• Dead: This group shows very little engagement with their inbox, likely created and abandoned. Dead accounts make up 9% of users in the panel and generate less than 1% of reads and complaints.

Frequency Optimization Depends on Engagement  This breakdown provides three important takeaways related to email send frequency:

• The most active and engaged subscribers are the most valuable, but they’re also the most sensitive—and the most likely to complain. Making changes to this group should be done cautiously, with the correct data and lots of testing.
• Secondary accounts, while technically an active inbox, are likely to be classified as inactive by some marketers. It’s difficult to make accurate decisions about send frequency and removal of inactives based on a typical dataset.
• Complaints don’t come from where you’d expect. “Inactives” aren’t the biggest driver of complaints, and varying send frequency to this group, either more or less, isn’t likely to make a difference in complaints or opt-outs, says the report.

Optimizing for send frequency requires an ongoing discipline of testing new send frequencies, collecting the right data, drawing the correct conclusions, and creating frequency recommendations for future campaigns, concludes the report.

• Primary subscribers are your most valuable and most sensitive group, they will be the most likely to notice (and react to) changes in send frequency. Test thoroughly before making any drastic changes that may not sit well with subscribers.
• Tracking only complaint rate when increasing your frequency, or total complaints when decreasing your frequency may be missing valuable insights. Use all the tools to measure success or catch the early warning signs of a failed campaign.
• Based on your tests and the resulting data, develop a send frequency strategy that will maximize email frequency according to subscriber tolerance.

 To access free complete report free, please visit here.