In the first quarter of 2006, the best email open and click rates were on weekends, according to online marketing firm eROI's most recent, Q1 2006 email study. Moreover, open and click rates increased significantly in the first quarter (40 percent and 60 percent increases, respectively), compared with rates for Q4 2005, when open and click rates decreased 29 percent and 21 percent, respectively, from the previous quarter.

The highest click rates in the first quarter were on Sundays - 6.6 percent - when the open rates were 25.9 percent, the second-highest open rate for the week. Tuesdays had the highest open rates at 26.4 percent, and the second-highest click rate, at 6.2 percent.

According to eRoi's April 2006 survey of email marketers (a fairly even distribution of B2B, B2C and hybrid approach - 38, 28 and 34 percent, respectively), email marketing lists are growing. Some- 83 percent of marketers see a significant increase in their lists from this time last year. Only 34 percent of email marketers use behavioral data for segmentation and targeting, whereas 66 percent use demographic information to position their offers and newsletters.

The Q1 2006 study also breaks down the open and click rates by mailer size: Micro-mailers (fewer than 5,000 recipients); small senders (5,000 to 24,999 recipients); medium-sized (25,000-99,999); and large mailers (100,000+). Large mailers - unlike their polar opposite small mailers - see poor statistics on the weekend.

But eRoi points out that the "important takeaway here is not what day is best for both opens and reads but finding which day is best for the goal of your email."

Prior coverage:

- Email Open Rates Fell in Q4, Peaked on Fridays
- Email Volume Affects Read and Click Rates, List Size Matters
- Best Day for Emailing Is a Moving Target
- Optimal Day of Week for Emailing Now Tough to Choose
- Email Send Day Studies Prove Self-Influencing