21 Words to Make Your Email Subject Lines Irresistible

First impressions make a huge impact in life, just like in email marketing. Here
are some of the best words that will make your subject lines attractive for your

No matter how sexy your email content is if your subject line sucks or makes you
end up in SPAM you’re busted. Fortunately there’s many information available on
the web about how to write killer subject lines and which words to use to make
your emails noticed.

Adestra - one of the
biggest ESP in the UK – analyzed over 2.2 Billion emails to figure out which words
work best. Here are the top 8 keywords they identified:

  • Free delivery
  • Available
  • New
  • Alert
  • News
  • Update
  • Summer
  • Weekend

We have to add that besides subject lines the frequency of email sending also had
a huge impact on open rates. Daily (+27.8%) and weekly (+27.1%) newsletters seem
to work the best (depending on industry) while monthly newsletters were opened
26.6% less.

Unfortunately there’s no information about how the time of the day influenced open
rates. The old “rule” seems to be mid-week + mid-day sending (1-3 pm) but don’t
take it granted, since for example another study showed that late night (8 pm to
12 pm) sending will bring you the highest open and click rates. There’s no golden
rule, so you simply have to invest your time to figure out what works best for you.

Alchemy Worx - a global email marketing agency -
conducted two different email subject line studies which looked at over 45 Billion
emails in total (21 Billion + 24.6 Billion). The most successful words seem to be
the following:

  • Upgrade
  • Just
  • Content
  • Go
  • Wonderful
  • Jokes
  • Promotional
  • Congratulations
  • Revision
  • Forecast
  • Snapshot
  • Token
  • Voluntary

“Magic” words

No matter how many emails were analyzed to get these results, don’t take these words too serious. Get inspiration from what you saw above, and craft your subject lines likewise. After you come up with 2 or 3 different subject line versions, always test them with people around you, with your colleagues, friends and preferably do A/B tests as well.

Don’t forget to personalize

75% of people love if they receive personalized messages. This is the primary reason why personalization increases click through rates with 14% and conversion rates with 10%. Basic personalization is quite easy, since you only need to include the name of the person, but advanced personalization can become quite complicated and you may even need to switch to a marketing automation tool instead of a classic ESP.

Do it your own way!

What works for one company may not work for another, and of course if you send out tons of email, you still need to renew your subject lines from time to time, since people will easily get bored if they receive the same stuff. No matter if it contains a HUGE discount or the magic word FREE (Use free with Caution).

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