An article by Raj Khera: Email Marketing: The First 48 Hours Are Critical which appeared in this month's Marketingprofs.com newsletter is well worth the read if you incorporate email-based marketing as part of your company's marketing mix.

"The next time you broadcast a permission-based email to your customers, members or newsletter subscribers, monitor your response for the next 48 hours.

That's when the vast majority—80%—of those who would open your message will actually open it, according to the results of our recent study. What's more, 95% of people who read your message do so within six days of your mailing.

The "Email Marketing Use and Trends Report: H1 2004" shows performance by industry for the first half of 2004, based on over 70 million opt-in email messages sent by MailerMailer customers. It includes delivery/bounce rates, unique open rates, click-through rates by industry; open and click rates by day of the week; and the effect of personalized subject lines and messages on open and click rates."

Note also the related article on MarketingVOX this week titled Email Send Day Studies Prove Self-Influencing. The article discusses research conducted by email firm ExactTarget who have released a study on the effectiveness of email campaigns relative to the days of the week emails are sent. Several earlier studies suggested that Monday and Tuesday have been the most effective days of the week. But the new study suggests that the best day for opening emails aren't necessarily the best days for conversions.

Further complicating things, ExactTarget showed that its own results matched a MarketingSherpa study published in July, yet after that MarketingSherpa study was released, so many emails were sent on Monday that the day came to be ranked fifth or sixth for subsequent quarters. ExactTarget found that emails sent Wednesday through Friday maximized open rates. Weekends tended to earn the most clicks per open, perhaps because only about three percent of emails are sent during that lull period.