Dive summary:

• Hubspot ran an email test to find out the effect of using "free" in mass email marketing.
• The first version had the word "free" in both the subject line and throughout the email's body while version B did not use it at all.
• Version B, the copy without "free," performed much stronger with a 17% higher click rate and 5% higher click-through-rate based on opens.

From the article:

Email marketing can be a tricky balancing act. You want to use copy that will get your recipients' attention, but you don’t want to select words that will raise red flags with SPAM filters.

But there's some good news! If you've been email marketing for a while (or even if you haven't), you might have heard that “free” is no longer a dirty word with the email overlords. Still, some email marketers are hesitant to use the word, just in case there's some truth to the former rumors.

Well, we decided to channel our inner Sherlock Holmes and do a little investigating. We tested it ourselves...