Subject Line Best Practices

Instill Curiosity:
Use teaser language that instills curiosity, but don’t be too vague.
Provide Incentive, Promote Action:
Tease offer (or mention directly if rich offer). If no offer, still use action words that inspire and instill a sense of urgency and incentive.
Short and Sweet:
Focus on the composition of the first 2-3 words. Keep your character count under 50. Utilize preview text for more context.
Personalization:
Make the member feel special and unique. Utilize first name, but be sure the name flows well within the subject line. Also, use segmentation when possible.
Avoid Spam:
Keep consecutive capitalization and punctuation to a minimum. Many marketers use emojis; only use them when the context makes sense.