US email marketing company MailerMailer released its Email Marketing Metrics Report this week, revealing practices to help businesses increase returns from their email campaigns.

Key factors highlighted in the report include the use of shorter subject lines, personalisation of emails, and targeted, well-managed lists. Campaigns using these strategies achieved higher then average open and click rates.

The report was based on over 200 million emails sent in the first 6 months of 2006. It revealed that emails sent on Mondays, Tuesdays and weekends achieved higher open and click rates, and that most recipients will open an email within a few hours of delivery, meaning that companies should expect the majority of customer responses within 2-3 days.

Subject lines were significant: 28.03% of recipients opened emails with personalised subject lines, and 6.23% clicked on them. This is compared to the 19.10% open and 3.28% click rate for average emails.

Shorter subject lines are also important, emails with subject lines of 35 characters or less were be opened by 24.02% of compared with 16.93% for  those with longer subject lines.

Targeted and well-managed lists emerged as a key factor in the report, with higher open and click rates achieved by campaigns targeted at fewer than 500 recipients.

In the internet category, 41.96% of emails targeted at fewer than 500 customers were opened, and 26.79% were clicked on. This contrasts with 13.81% opened and 5.2% clicked on for campaigns of 1,000 or more recipients.

The full report is available to download at