Tools and Tips for Testing Your Subject Lines

July 13, 2008

Since the release of Alchemy Worx’ subject line study in June, there’s been a lot of buzz in the email industry about subject line length.  I won’t go into the details of the different discussions, because at the end of it all… there’s no real answer as to how long or short your subject line should be! 

The only real answer is… to keep testing.  (I hate to say this, but  I will …. I told you so! See my previous post about “Testing, Testing, Testing…”)

Dela Quist, CEO of Alchemy Worx herself says “My greatest fear is that the people reading the whitepaper will be looking for a simple answer such as “when it comes to email subject lines, short is best”, when in fact the central message is keep searching, keep optimising and keep on challenging assumptions.”

Truth be told, if there’s any one thing in your email that needs constant testing, it’s the subject line. As I mentioned before, the envelope fields (the “From” and subject lines) are the two most important elements of your email, as they ultimately determine your email’s fate.

Email filters scan subject lines for SPAM-like text and can block an email before it’s delivered to the recipient.  Assuming your email gets through the filters, it’ll still be judged as SPAM (or not) by your recipients, based solely on the contents of the FROM and SUBJECT lines.

• The “From” line is what your readers use to determine whether or not to delete an email.
• The Subject line is what motivates them to actually open the email.

Now since the FROM line stays constant (if it doesn’t… IT SHOULD!), it’s your subject lines that need the most attention… so here are some great (and yes, free) tools that can help:

1. Direct Services, Inc’s Email Subject Line Tester -  I love this.  Just type in your subject line, and the program will check it for “spamminess”, and generate a chart which looks like this:  (click for a larger view) 

 The Email Subject Line Tester uses a series of quantitative and qualitative algorithms, extracted from static and live databases, to arrive at an indication of what might be considered SPAM.

• A GREEN checkbox indicates that no warning flags have been triggered that would indicate SPAM.
• A YELLOW checkbox indicates that a score for a component(s) of the subject line’s text is approaching a filter threshold where the email might be perceived as SPAM.
• A RED checkbox indicates that a score for a component(s) of the subject line’s text has exceeded a filter threshold where the email will very likely be perceived as SPAM.
• More RED checkboxes triggered by a particular subject line indicates the email has a greater likelihood of being considered as SPAM.

2.  EmailLabs’ Envelope Field Preview Tool -   This is really useful because it shows how different email clients will render your email’s From and subject lines.  (Length varies depending on what email program you use). 

You can use this to see how your envelope fields will display in Outlook, AOL, Yahoo, Hotmail & MSN, Eudora, Excite and juno. Enter your email from name, from address and subject line - and then press preview. 

(Note though, that this is a pretty old resource, and may not account for recent changes made to the programs of different email clients.  In spite of that, it’s still a pretty good guide.)  

 

IMPORTANT:  These are neat pre-campaign tools, but bear in mind that the REAL testing (the only type that counts) can only be done when you actually send.  Perform regular split tests using different subject lines, and keep a close eye on your stats to see which generates the best results (i.e., open and clickthrough rates). 

Mailchimp has an A/B split testing feature built into their program, which is the one thing that really won me over, but you can do split testing no matter what program you use.   Just remember that for your test to be valid, EVERYTHING EXCEPT THE SUBJECT LINE must be exactly the same.  Otherwise, you’ll skew your findings.

So really, no matter what or how much research is done in the field of email marketing, one thing will always remain constant.  You will ALWAYS have to test.  There are no set answers — only better ways and methods to test, and recommendations on what to look for.  

To see the findings and recommendations from Alchemy Worx’  Subject Line study, click here to download their whitepaper.