The Secret to Successful Email Marketing: Testing

Email Marketing


Hate it or love it, email marketing is here to stay. According to a recent CSO Insights survey, email marketing was the top lead generation program based on quality and quantity of leads. So, the million-dollar question remains: How do I better leverage email marketing?

Figuring out what works and what doesn’t work in your email marketing campaigns takes more than an educated guess, it requires patience and constant fine tuning.  Knowing which subject line, offer or other aspect of your email generates the highest open or click-through rate can be the key to reaching more, qualified prospects. Although there isn’t a silver bullet, you can start by considering what metrics to measure, your expected results, and continually test, test, test!

Testing important factors impacting opens (i.e. subject line) and click-through (i.e. offer, content length, link placement) over and over will help you narrow down the best email marketing campaign for your business and your audience. You can think of testing as a 3 step process: 1) figure out what variable(s) to test; 2) create multiple versions of the email (version A and B); 3) distribute version A to a portion of your list, and version B to the other. Note – make sure your sample size is large enough. Of course, the target audience and relevance of the message are by far the most important factors in determining how well an email performs; you still want to optimize all the other variables of the email.

Over the past three months, I took this advice and conducted over 15 A/B split tests to discover what resonates well with my target audience.

Here are some of the variables I tested:

  • Subject line
  • HTML vs. text versions
  • Graphics vs. no graphics
  • # of links and link placement
  • Offer
  • Content length
  • Message style

Here are some of my findings:

Subject line

  • For event followups: Put the event name in the title
  • For invites: Personalized, yet tempting hook (ex: thought you might be interested in xyz)

HTML template with graphics

  • A graphically appealing message still works. Use clickable email banner, buttons, and heroshots/images

# of links

  • The more the merrier; min = 2, max = 4
  • Linking the title or name of the offer works better than “click here”, make it easy for the reader to see what they’re getting


  • The offer has to be obvious at first glance
  • Highlight the key highlights of the offer via bullet points, which is much easier to read than a block of text
  • Doing a event recap blog post is a hot offer, especially after a tradeshow

Content length

  • 3-4 total paragraphs + bulletpoints
  • Short content doesn’t always win, make the content compelling and flow nicely into the call to action

Message style

  • Personal touch beats out generic message (seems obvious): Use of tokens; “forwarded” messages
  • Influential tone (peer pressure) edges out passive tone

For the rest of the year, I plan to continue testing these variables, and others, in order to solidify what works best. It’s always good practice to review your tests, so you can draw conclusions and continue to improve. After all, email marketing is here to stay.