- Have something to say that's new, timely or “on sale.” Get it into your subject line and it's sure to pay dividends.
- Say it in CAPS if it's important enough. Consider anchoring your subject line with: “INSIDE,” “BREAKING NEWS” or “CONFIRMED.”
- Consider testing “free” as a visual hook, especially if you're giving away a white paper, premium, etc. One of my b-to-b clients witnessed a conversion-rate boost of 45%, even though some messages were no doubt captured by spam filters. Proof of the enduring allure of “free.”
- Got two messages? Test a combined subject line. For example: Introducing New Power Boost|ETW an iPad
- Put a date, price or dollar figure in your subject line. Numbers stop the eye and boost open rates.
- Don't forget “From” line testing, too. After all, what do you look at first when peeking at your inbox?
- Last, be sure to test wisely. One rule of thumb says you need 300 responses, or opens, per test panel to ensure your A/B test results are valid at a 95% confidence level. For small and midsize businesses that don't have the universe to test at this level, use what you have. Go ahead and test two panels of 800 if that's all you can spare. Then blast your message using the winning subject line.
Kate Maddox on 03.02.2015