E-Mail Applied: Beware the Danger of High Frequency E-Mail

• Revenue increase. This likely will be stronger with a stepped-up mailing schedule. Are you trading short-term revenue gains for long-term losses?
• Revenue per delivered e-mail. This is the statistic that tells all.
• Opt-outs. Does frequency have a direct impact on your list size?
• Spam complaints. High complaint rates put your e-mails in danger of being blocked by ISPs or sent to bulk folders.
• Bounces. If you're sending more e-mails, naturally you'll have more bounces. As a result, more of your list will be moved to a do-not-e-mail status over time.
• Open and clickthrough behavior. If you don't get opens, you're not engaging your list. Mailing to a list that's increasingly inactive can be a problem. Plus, low open rates impact your reputation with some ISPs.

This analysis takes time and discipline, but yields an assessment of your e-mail program's health. I've seen examples of 40 percent revenue increases with more frequent e-mails. But the revenue per delivered e-mail is about half, and opt-outs are more than double.