Many marketers mistakenly summarize their entire email in the subject line, removing any incentive to open it. To increase curiosity, provide only a hint or a compelling data point from the email's content. This creates an information gap that subscribers feel compelled to close by clicking.

Contrary to old advice, adding a newsletter edition number to the subject line is now highly effective. Specifically, putting the edition in brackets (e.g., "[Scoop #12]") before the main subject line has been shown in A/B tests to increase open rates by approximately 20% compared to a standard subject line.

A counterintuitive tactic suggests beginning email subject lines with conjunctions like 'and,' 'but,' or 'plus'. This grammatically incorrect but novel approach disrupts reader expectations, sparking curiosity and leading to a claimed 15% lift in open rates, especially when the starting word is capitalized.

Contrary to old email marketing wisdom, testing fully capitalized subject lines can significantly increase open rates by 3-4 percentage points. Modern spam filters are less likely to penalize this tactic, making it a viable test for grabbing attention in a crowded inbox.

Switching from clear but safe subject lines (e.g., '3 ways to...') to provocative, curiosity-piquing ones dramatically improved open rates. The speaker notes that if a subject line feels slightly uncomfortable to send, it's probably a good sign.

A counterintuitive yet effective email tactic is capitalizing an entire word in the middle of a subject line, not at the start or end. This simple, cost-free A/B test is trending because it breaks visual patterns in the inbox, leading to a reported 16% open rate increase for B2B and 21% for B2C.

Many marketers mistakenly reveal the entire value of an email in the subject line, killing any reason to open it. To maximize opens, provide a compelling hint or create a curiosity gap rather than giving away the full story.

To make an email stand out, use a subject line under three words and remove the preheader text. This creates visual white space around your message, distinguishing it from the 98% of emails that use preheaders. This visual disruption can skyrocket open rates.

Contrary to previous best practices, adding a newsletter edition number in brackets within the subject line is now highly effective. Recent A/B testing reveals this tactic can increase open rates by approximately 20% compared to using a standard subject line alone.