According to new research from Adestra, analyzing 1.159 billion B2B emails sent within the last 12 months, the subject lines that work best are either less than 30 characters, or longer than 90 characters. The in between lengths they report as a “dead zone.”
Character length, says the report makes a difference. The study found that Using 90 characters and upwards produced the highest response rates because more benefits can be communicated by using more characters. In contrast, snappier subject lines that used 30 characters or less performed well in the case for transactional or direct-action emails.
Normaly, says the report, word count is a proxy for character count, and vice versa. But in a B2B context, where industry-specific jargon tend to be long words, it’s important to consider this metric.
Word count results in the study produced similar results to the character lengths in that each end of the count scale performed the highest. However the comparative results show that much shorter subject lines (14 or fewer words) produced considerably higher engagement than longer subject lines.
The prevailing notion is that using currency symbols in subject lines might be considered spam. However, spam filters use Baysian Filters to determine spam ratings, and in the B2B world, users engage strongly with currency symbols, and spam filters no longer penalize for their inclusion. Engagement, though, is only high when relevant and valuable financial email content is communicated in the subject line.
Analysis and reporting from Marketing Charts yielded an excellent summary of the actual metrics of word choice and positioning, and is included here.
Social networks in general elicit a poor response rate. This could be due to the huge volume of emails pertaining to them, or it could be an indication that in the B2B world people aren’t using social networks as much as pundits had predicted.
Personalized Subject Lines
With personalized subject lines, recipients feel instant engagement, but Engagement falls off when people open the email, since in most cases the content of the emails is not personalized! The key here is to construct a congruous user experience, says the report.
In summary, the Adestra report concludes that there’s no one-size-fits-all option. The only common denominator in this study is that testing your subject line approach is key. This study provides a starting point for assessing how to develop the subject line testing strategy.