SMS A/B Testing: How to Discover What Makes Your Customers Buy

Guessing ≠ marketing

You know the most expensive thing in marketing? Keeping doing what isn't working. And the cheapest? Testing what does work before you put full budget behind it.

SMS A/B testing is simple: send two different versions of a message to two small groups, see who won, and send the winning version to everyone else. Simple? Yes. Do people do it? Almost no one. And that's exactly what gives you the edge.

What do you test in A/B testing?

1. The message opening

The first words decide whether the customer keeps reading or scrolls past.

Version A: "This week's deal! 30% off…"

Version B: "[name], we saved you something: 30% off…"

Personalization (customer name) usually wins, but not always. In some campaigns a direct, strong phrasing works better. Without testing — you won't know.

2. The offer itself

Version A: "30% off everything!"

Version B: "Free shipping on any order!"

Surprise: in a lot of cases, "free shipping" beats "30% off" — even when the discount is worth more money. People hate paying for shipping more than they love discounts. But — it depends on your audience.

3. Call to action

Version A: "To shop click here: [link]"

Version B: "Come in now: [link]"

Version C: "[link] (until midnight!)"

Urgency can double click rates. But overuse makes people ignore it because "there's always a deadline."

4. Emoji — yes or no?

Version A: "Special deal for you! 🔥🎉"

Version B: "Special deal for you."

Depends on the audience and industry. Restaurants and fashion? Emojis work. Law firm? Probably not. Test.

5. Timing

An A/B test many forget. Send the same message — but at different hours.

Version A: Sent at 10:00 AM

Version B: Sent at 14:00 PM

For online stores, 20:00–22:00 sometimes beats all hours. People at home, with the phone, nothing to do. But for restaurants? 11:00 AM is gold.

How to run A/B tests properly

Step 1: Pick one variable

Don't change everything at once. If you changed the text and the hour and added emojis — you have no idea what caused the difference.

Step 2: Split the audience

Take 20% of your list — 10% gets version A, 10% gets version B. The remaining 80% wait.

Step 3: Give it time

In SMS, an hour or two is enough to see results. Most clicks happen in the first 30 minutes.

Step 4: Pick a winner

The version with the higher click or conversion rate? Send it to the remaining 80%.

Step 5: Document

Save the results. After 10 tests, you'll have a body of knowledge about what works with your audience — knowledge no competitor can copy.

Results from the field

An Israeli online store ran A/B tests on 12 consecutive campaigns. At the end:

• Click rate went from 8% to 16% (2x!)

• Conversion rate rose from 4% to 9%

• ROI on SMS campaigns rose 180%

And all that changed? They stopped guessing and started testing.

Start testing

Vibrate has built-in A/B testing: define two versions, pick a test percentage, and the system automatically sends the winner to everyone. Sign up free and stop guessing.