Reward Arrival, Survey Emails Perform Best
Looking at different categories of loyalty mailings, the study finds that reward arrival emails have both the highest transaction rate (1.4%) and revenue per email ($6.81). While survey emails have only a slightly higher transaction rate than renewal emails (0.9% vs. 0.8%), they have a much higher revenue per email ($3.86 vs. $1.60).
Statements and welcome emails also have high transaction rates (0.7% and 0.6%, respectively), although revenue per email is much higher among statement emails ($1.82 vs. $0.80). Despite having comparatively low transaction rates, redemption reminder and status-level emails have relatively high revenue per email, at $1.26 and $1.62, respectively. Meanwhile, loyalty promotions have just an 0.1% transaction rate and $0.11 revenue per email.
Shorter Subject Lines Get Better Open Rates
Among promotional emails, subject lines of less than 26 characters had on average the highest unique open rates across all industries save for Business Products and Services, where those of more than 76 characters had the best open rates (20.1%). The discrepancy in open rates between short (<26 characters) and long (>76 characters) subject lines was most apparent in the travel industry (28.9% vs. 19.6%), with open rates only differing by 1-2% points for most other industries.
The trend for shorter subject lines to have better open rates was also found recently by Informz, in a report released in March. Examining more than 600 million emails sent by over 700 large and mid-sized associations that used its email marketing platform in 2011, Informz found that subject lines less than 10 characters long boasted an open rate of 58%, 38% higher than the next-highest open rate, for subject lines of 50-59 characters in length (42%).
Discount Keywords Seen More in Subject Lines
Data from Experian’s “The 2012 Digital Marketer” indicates that words referencing discounts or offers grew rapidly in 2011 when compared to the previous year. For example “% off” was contained in 11.3% of marketing emails, up 18.1% year-over-year, while the use of “50%” saw the biggest increase, of 30%.
“You/your” was the most common word(s), used in 18.7% of subject lines, up 3.4% year-over-year, followed by “off” and “get,” both in 16.6% of emails, and both up 5.2% year-over-year.