Retarget users that have fallen dormant. As per 500.co, between 60-75% of subscribers on the average email list are dormant– they haven’t opened an email from that list in at least six months. An AdRoll survey showed that 90% of marketers said that “retargeted ads are as good or better than the gold standard in digital marketing.” Using paid ads or email to retarget dormant subscribers with a new offer can be exceptionally effective.