Final answer:
To optimize an email campaign with low click-through rates, it is essential to optimize the content, segment the audience to alter targets, and potentially adjust the frequency, with caution to avoid over-sending.
Step-by-step explanation:
If Sal notices that the last email campaign had low click-through rates, to optimize and improve performance, he might consider a few different strategies.
Firstly, optimizing email content is crucial; this could involve making the content more relevant, engaging, and personalised to the recipients' interests to drive more clicks.
Secondly, altering the target of the emails by segmenting the audience and tailoring messages to different groups could lead to better engagement. Finally, increasing the intensity or frequency could potentially boost performance, but this tactic must be used carefully as too many emails can lead to subscriber fatigue and have the opposite effect.