The document provides tips for writing effective email subject lines to increase sales. It suggests focusing on encouraging giving, helping customers, and engaging with interesting content. Specific techniques recommended include giving something away first to get attention, helping customers find time for your message in their busy schedules, and using holidays and sales periods to share more than just shopping information. Examples of subject lines that work well are also given such as those mentioning gifts, stress-free gifting, and interesting articles or travel ideas. The overall message is that email remains one of the best ways to reach customers so marketers should make every subject line count.