To gather insights on optimizing short-form customer content, that generally starts with a powerful subject, tagline CTA that grabs attention quickly and encourages engagement.
Questions you could ask:
"Are you motivated to take action after viewing the below content?"
"Which of the following taglines makes you want to click on it the most?"
"What subject line is most appealing to you that would most likely make you want to open the email?"
"When you see social ads, which button directive (aka call to action) makes you most like to engage (promo, review, more information, contact details, other)?"