“Hey".

Who would have thought that an email with a one word subject – "hey" would be the key to President Obama's email campaign that kept him in the White House for another 5 years?

As it turns out, the casual, informal tone worked way better than being all official and presidential.

We know this because the digital team during that campaign were obsessive about testing these things. In one experiment, they tested 18 different combinations of emails and subject lines and sent different versions to small groups of subscribers to see which one won.

The results were telling:

They ran around 500 A/B tests like this. Pitting each idea head-to-head to fight it out in the real world.

They tested different page designs, email subjects, email copy, images, the works.

And all these improvements stacked up to create a massive compound effect.

161% Sign up increase x 49% Donation increase = Combined 289% increase

In the end, Obama's team raised $690 million in campaign funding and most of it came from these emails.

As to the politics, it doesn't matter a jot. Love Obama or hate him, you have to admit that the campaign team showed some serious business chops, right?

They may have literally changed the course of history … just by changing around a few words.

The tricky bit is always figuring out exactly which words to change, which is why we added A/B testing right inside our List Builder app in Sumo.

You no longer need to rely on your spidey senses to tell you what works best.

Now you'll be able to use scientific data instead of superstition.

It's a List Builder Pro feature, but this month you can unlock a 1 month free trial in your Sumo Store and start getting more email subscribers. %(productlink:list-builder-pro:[Click here to go Pro now])

Here's how to setup your first A/B test (you must be on List Builder Pro):

%(abpro)

And here are a few examples of what to test –

1. Test Your Headline

• [A] "Join the Email Wizardy list"
• [B] "Free email course – From zero to 78,149 Instagram followers in 28 days"

2. Test Your Subheadline

• [A] “Be first to know updates”
• [B] "You'll also get the checklist I used to add 73+ email subscribers a day with Instagram".

3. Test Your Button Text

• [A] "Subscribe"
• [B] "Make me an A/B testing Jedi"

4. Test Your Design

• [A] Style your button to match your site
• [B] A bright yellow / blue / green button that jumps off the page

Think this list is loaded in favor of option B?

The truth is, you never actually know until you test it on your site with your audience.

A reserved headline might work on a luxury site that sells Rolex watches but it could totally bomb on BuzzFeed where the only currency is attention.

You don't need to run 500 tests like team Obama to figure it out. That's borderline obsessive.

But adding your first A/B test will give you some massive insights into how your customers really think.

Unlock your List Builder Pro account now in your Sumo Store and set up your first A/B test. %(productlink:list-builder-pro:[Click here to do it now])