Everyone loves being invited to a friend’s birthday party on Facebook. Recently, I was invited to my friend Jane’s birthday party. Here’s what the email looked like in my inbox:

What was really effective at getting me engaged was that my friend’s name Jane Smith was in the from field of the email. This way, it appeared that she, personally, had sent me the email.

Shortly thereafter, I saw another email arrive in my inbox. My friend had updated the original invitation:

Now, instead of being from my friend, the email was from Facebook. So when I first glanced at the email in my inbox, I had less urgency to see what it was about because it didn’t appear to be arriving directly from my friend. My guess is that Facebook has AB tested the original event creation email subject and found that replacing Facebook with the event creator’s name in the From field leads to greater engagement. As a next step, they can either AB test the same change for the event update email or simply implement the change.