MarketingSherpa recently released the results of a study asking close to 1,500 marketers what email elements they test frequently or plan to test -- using techniques such as A/B split or multivariate testing -- in order to improve the effectiveness of their email marketing campaigns.
The chart below shows that subject lines remain the most frequently tested element, but that other items such as "calls to action," send time and creative/copy, are being tested nearly as frequently. MarketingSherpa speculates that the reason for broader testing is that "tweaking" elements based on testing can produce dramatic improvements in campaign results and has proven to be well worth the time and effort required.
Interestingly, B2C marketers test all email elements more heavily than B2B marketers.
Of course, firms must work with email services providers that offer "testing" capabilities (performing A/B testing, for example, requires the ability to segment large lists randomly into two smaller equal-sized lists).
Read more about the study on MarketingSherpa.