Use Review Data in Marketing Email Subject Lines

Adding star ratings and review counts to your marketing email subject lines creates a trust signal that stands out in the inbox. "Our #1 Rated Moisturizer (4.9 stars, 1,200+ reviews)" outperforms "Shop Our Best-Selling Moisturizer" by 15-20% on open rates because it provides objective evidence rather than marketing claims.

Use review data strategically across different email types. Product launches: "Just launched — already 4.8 stars from early customers." Promotional emails: "Our highest-rated products are 20% off this weekend." Win-back campaigns: "2,500+ customers gave this 5 stars — see what you are missing." Each format uses social proof differently but achieves the same goal: credibility.

Dynamic review data in email subjects keeps them fresh and authentic. If your email platform supports dynamic content, pull the current star rating and review count at send time. This prevents stale data and ensures the numbers always match what customers will see on the product page.

A/B test review data placement within subjects. Some audiences respond better to review data at the beginning ("4.9 stars — Our best moisturizer is back in stock") while others prefer it as supporting evidence at the end ("Our best moisturizer is back — rated 4.9 by 1,200+ customers").