Thinking about using symbols in your email subject lines?

Using symbols in your subject lines can be a great way to vary your email messaging, keep subscriber interest up or spark new interest with subscribers who were previously unengaged.  At Experian CheetahMail, we have seen mixed-to-positive results when using symbols in subject lines, with 56% of brands we analyzed having a higher unique open rate.

What is a symbol? The most popular symbols we’ve seen in subject lines (in order of popularity) are:

♥ ★ ☼ ♫ ☀ ✿ ☆ ♡ ⇒ ☺ ❤ ✈ ✞ → ☂

Every font set (like Helvetica, Arial, and Times New Roman) is made entirely out of “symbols.”  Special symbols, like hearts and stars, are based on the Unicode computer industry standard character set, which are different from images.  Out of the hundreds of thousands of possible Unicode characters that exist in computing, each one of these characters can possibly be used as a symbol in a subject line. Some clever marketers even use them in combination.  For example, ☀|||||||☀ was used in an email for Jeep, representing the recognizable front of a Jeep with the headlights and 7-slatted grill.

While marketers may be able to get creative with symbols in subject lines, there are thousands of possible symbols and combinations and each character may or may not exist in the font and/or encoding method used by each browser and email client.

So, what symbols can I use in my emails?

Because there are thousands of characters or symbols which can be used in subject lines, no complete “master list of email symbols” exists.  You can, however, get a good idea of what’s in common Unicode Blocks and use the “my browser” view to identify symbols that are likely to work in an email subject line.  The best way to know if a symbol will render is to test it.

Symbol Fun Facts:
  • Subject lines with symbols had a higher unique open rate in 56% of brands we analyzed
  • The black heart (♥) is the most popular symbol, but provided only a modest open rate lift of 2.2%
  • Of the 5 most popular symbols, the black sun with rays had the highest lift in open rates (14.9%)
  • Trying a different symbol may add a ‘wow’ factor to subject lines.   Airplanes (✈) had a 10.7% lift in unique open rates, while umbrellas (☂) generated a 50% lift

Remember, symbols should make sense.  If you test using symbols in your subject lines and see great results at first that taper off, perhaps the “newness” has worn off. Try testing new symbols or testing symbols against no symbols.

For more information on using symbols in subject lines, download Experian CheetahMail’s whitepaper “Symbols in subject lines: An in-depth look at symbols.