Mar 4, 2008

Does “FREE” Make People Open Your Emails?

I recently blogged about some interesting A/B Split data that I’ve been sifting through for a report we’re working on.

Thought I’d post another interesting observation from a handful of campaigns that ran A/B Split Tests on their subject lines (company names disguised as "Acme"). The first 4 are from the same company, sending emails for 4 different web properties that they run…

Winning Subject Line (by open rate) Losing Subject Line
Acme News Update Free Shipping Until Valentine’s Day
Acme Store News Free Shipping Until Valentine’s Day
Acme Store News Free Shipping Until Valentine’s Day
Acme: Store Update Free Shipping Until Valentine’s Day
20% OFF book bundles, FREE book raffle, NEW books NEW books, FREE book raffle, 20% OFF book bundles
Free Dinner! Save Time and Money!
ACME January "100 Dairy Free" Book Give Away Acme January Newsletter
Hurry! Shipping is free through Wednesday Free Shipping Through Wednesday
The Perfect Valentine’s Day from James Free! Valentine’s Dilemma? We’ve Got Great Gift Ideas!
Take the Girlfriends on vacation! Free Food! Free Assembly!
Acme Brain Push Up Free Acme Ending
Acme trial expiring: Keep your brain sharp Free Acme Ending
Free Acme Ending Play Great Brain Games

In almost all the examples above, the subject line with "free" had a lower open rate. So should you avoid the word "FREE" in your subject line? In my opinion, don’t use "free" if it detracts from relevance. If you replace your company name with "free" or if you remove the urgency with "free," your open rate is going to suffer.