Flint McLaughlin of MarketingExperiments.com (which bought Sherpa late last year) offered a cool formula for assessing the effectiveness of an email campaign, as follows:
Effectiveness = 3lq + 2t + 2r + 2bc + e + d
lq is list quality
t is timing
r is relevance
bc is body copy
e is invelope info (preview pane, from and subject line)
d is deliverability
Translated into English, this means that based on MECs multiple regressions, list quality is the most important determinant of success. One tier down are the timing of the campaign, relevance to your target audience, your copy. One tier below that are the envelope info and deliverability.
What makes this formula useful is it gives lots of hints about where you should be investing time and energy. If you are doing envelope testing (or, God forbid, subject line testing), please stop.
Flint did not define what he meant by “list quality,” and I am sure he is thinking in part about technical factors. I’d add to the definition of list quality that people on the list know who who you are, appreciate past communications from you, and feel bonded to your organization. While we strongly counsel against hammering your list with donation asks, every communication to a donor should have cultivation as an objective.