One of the most important things people lack in this day and age is time. As a business, thinking about this in your communication with your clients can make or break the communication. Translating this through emails, and email marketing, it means people can be very quick to ignore and delete an email if they don’t have a very good reason to open it. An effective subject line in a business email is often critical for maximum results. So, the important thing is to find words that have a high influence on the opening rate, compared to those that might hamper the opening rate.

Effective words in the subject line have proved that they intrigue the customer's mind to open the email, and influence the overall communication contained within the email. To serve the purpose in a better way, in-depth research has been carried out by Alchemy word, using the Touchstone platform; analysed the data of 21 billion marketing emails from 2500 different brands. The investigation comprised the analysis of subject lines, word by word, to conclude their effect on open rates.

Table I: Best words for email Subject Line

Best Words    
WordOpen Rate (vs avg)Rank
Jokes 117% 1
Promotional 70% 2
Congratulations 68% 3
Forecast 56% 4
Token 40% 5


Table II: Best words vs Worst words

Best Words     Worst Words  
WordOpen Rate (vs avg)RankWordsOpen Rate (vs avg)
Jokes 117% 1 Suburbs -50%
Promotional 70% 2 Decoder -49%
Congratulations 68% 3 Inland -49%
Forecast 56% 4 Wish -38%
Token 40% 5 Third -36%


The words that have negative impact on the open rate are termed as worst words. The data indicates words that have negatively affected the open rate are Suburbs -50%, Decoder -49%, Inland -49%, Wish -38%, Third-36%.

Some additional findings of the report are given below


Clients have showed mix response to different symbols in subject lines. Data is given in the table below for best symbols and worst symbols, for increased open rate and negative effects on the open rate.

Table III: The Best and the worst Symbols

Best Symbols     Worst Symbols  
SymbolOpen Rate (vs avg)RankSymbolOpen Rate (vs avg)
65.72 1 -9.52%
20.95 2 -8.10%
10.65 3 -8.03%


Industry Data

The researchers studied open rates for five different strata of industries i.e. travel, retail, media/entertainment, technology, and consumer services and noticed vertical-specific variations for each. Tables for each of five different strata is given below.

Table IV: Best and Worst for Travel

Best Words     Worst Words  
WordOpen Rate (vs avg)RankWordsOpen Rate (vs avg)
About 26% 1 Midlands -2.4%
Tell 23% 2 East -2.3%
Remember 19% 3 South -2.0%
Plus 11% 4 Departing -2.0%
Holiday 7% 5 Last -2.0%


Table V: Best and worst words for Media & Entertainment

Best Words     Worst Words  
WordOpen Rate (vs avg)RankWordsOpen Rate (vs avg)
Content 59% 1 Monday -3.4%
Important 53% 2 Furry -3.1%
Expired 40% 3 Grade -2.9%
Information 39% 4 Nite -2.9%
Renew 37% 5 Double -2.9%


Table VI: Best & Worst words for retailers

Best Words     Worst Words  
WordOpen Rate (vs avg)RankWordsOpen Rate (vs avg)
Painting 18% 1 Groovy -4.3%
Ships 13% 2 Friday -4.0%
Please 7% 3 Volunteer -3.6%
Notice 6% 4 Fifty -3.5%
Recipe 5% 5 29% -3.0%


Table VII: Best & Worst words for Technology

Best Words     Worst Words  
WordOpen Rate (vs avg)RankWordsOpen Rate (vs avg)
Upgrade 66% 1 Miss -4.6%
Just 65% 2 Deals! -4.4%
Go 56% 3 Out -3.6%
Better 54% 4 Year -2.7%
Deserve 54% 5 Learn -2.6%


Table VIII: Best & Worst words for Consumer Services

Best Words     Worst Words  
WordOpen Rate (vs avg)RankWordsOpen Rate (vs avg)
Wonderful 55% 1 Conditions -4.0%
Several 31% 2 Vacation -4.0%
Sleeps 31% 3 Penny -3.9%
Waiting 22% 4 Finances -3.8%
Just 21% 5 Healthy -3.8%



Nanji. A. (2015) The Five Most Effective (and Ineffective) Words in Email Subject Line. Retrieved from

Jennings. J. (2014).The Best and Worst Words to Use in Subject Lines – New Research Retrieved from

ADAY.D. (2015) Email Subject Line Advice From Marketing Experts Retrieved from

MacDonald. A. (2013) The Effectiveness of Symbols in Email Subject Lines. Retrieved from