Inbox Competition Calls for Testing

Friday is the current favorite of a few email service providers (ESP). However if a large number of marketers move their mailings to a Friday schedule, it will cause inbox competition. Research released by ExactTarget recommends testing to determine the best day for individual organizations to send newsletters.

According to the report, Friday consistently averaged the highest open rate in a 14 month period from October 2005 through November 2005. Friday averaged 39.6 percent, Thursday’s open rates were 39 percent, and open rates for Tuesday and Wednesday each averaged 38.4 percent.

Clickthrough rates are highest on Sundays, with a 6.9 percent average. Friday ranked second highest with 6.5 percent; while Monday and Thursday each experience an average 6.4 percent clickthrough rate.

While Friday looks like the best day of the week for sending, the study’s author, Morgan Stewart, director of strategic services at ExactTarget, says the best day to send email newsletters is a constantly moving target. “Friday seems to be what [ESP providers” are agreeing on at the moment,” he said. “When people switch to Friday, results change.”

Send activity is focused on mid-week, meaning Friday has less email traffic and fewer emails are therefore received by consumers. About 96 percent of campaigns, and 92 percent of email volume are sent Monday through Friday.

Regardless of the day email newsletters are sent, marketers must understand the competition for attention in consumers’ inboxes. “An organization may have clearly defined competitors in the general marketplace, but its competitors in the inbox can be drastically different,” said Stewart. “Organizations are competing for the attention of their subscribers.”

Stewart recommends testing through A/B splits or controls, and compulsory month-to-month testing to determine the best day to send newsletters and campaigns. “Go ahead and consider Friday as a viable challenger, but don’t make a hasty switch to Friday and think it will work out without testing what the results are for your particular organization,” he says.

The data are part of ExactTarget’s “2005 Response Rate Study.” It’s based on data collected through the ESP’s emails sent during the 2005 calendar year. The study analyzed 12 months of historical data from over 4,000 organizations, 230,000 email campaigns and 2.7 billion email messages. The company calculates open- and clickthrough rates separately.