Email subject lines: the best words to boost open rates

Crafting good email subject lines that will appeal to a vast, unpredictable host of customers is inherently difficult. The difficulty is trying to find a system or style to use every time without getting repetitive. I can’t give you any magic lines to copy and paste because it has to be personal to your business, and reflect the tone of your brand – however I can help you identify the words that increase and decrease open rates.


Take a look at the table above, this analysis was done by Alchemy Worx. They show us that the words content, policy and offer are the top 3 words for increasing open rates whereas Friday, Monday and Double decrease them the most.

I find this somewhat perplexing – “content” doesn’t have particularly positive nor negative connotations, however, if it works I can’t knock it. The word policy receives an unsurprising high open rate, as it indicates important information (e.g. Online Banking Policy Documents). You will also notice that days of the week have particularly bad open rates; could this have been affected by the masses of emails promoting Black Friday and Cyber Monday?

It is important to remember that these stats will vary by industry. For instance, the most popular words in the financial sector are ‘policy’, ‘benefits’ and ‘premium’ which leads you to believe that the overall results are heavily influenced by this industry.

However, the best words for the travel industry are ‘Holiday’ and ‘Voucher’ although I would advise you to avoid using ‘departing’ or any points of the compass.

Conclusively, I don’t want you to walk away from reading this article and trying to cram as many of the positive words into your email subject lines as you can – they may not affect your email campaign at all, but it’s worth considering. It’s also important to toy with the sending frequency of your emails, when you’re sending them etc; these can all be massive contributing factors to your open rates.

If you don’t believe me, try it yourself. It can’t hurt, surely? If you feel you need a helping hand with your twitter advertising make sure you get in touch. Sharp Monkeys is a digital marketing agency based in Worcester.