This ad broke the rules — and it worked

There are thousands of guides online about the “right” way to run ads.

• Keep the text short.
  

• Use clear CTAs.
  

• Avoid negative messaging.
  

• Always highlight the benefit first.
  

And yet, some of the most memorable and effective ads are the ones that broke those rules.

Take Oatly’s “Wow, No Cow” campaign.
Instead of sleek product shots and benefit-driven copy, they plastered giant billboards with awkward, hand-drawn doodles and self-deprecating lines like:
“It's like milk but made for humans.”

By textbook advertising standards, it was “wrong.”

• The copy was clunky.
  

• The visuals looked unpolished.
  

• It didn’t hammer home features or pricing.
  

But it worked.

Why?

1. Rule-breaking creates attention
   We’re so used to scrolling past formulaic ads that when something looks “off” or “too simple,” it forces us to stop. Oatly leaned into that tension.
   

2. It matched their brand voice
   The scrappy, anti-corporate style wasn’t just an ad gimmick—it was Oatly’s identity. Breaking the rules worked because it was authentic, not forced.
   

3. It gave people something to talk about
   The ad wasn’t just selling oat milk. It was sparking conversation about why dairy alternatives exist and poking fun at the industry itself.

🔑 Takeaway for marketers:
Breaking the rules only works when it’s intentional and aligned with your brand.

• If your identity is disruptive, polished ads might hurt you.
  

• If your audience loves authority and trust, you probably shouldn’t run a chaotic campaign.
  

Sometimes the best move isn’t to follow the playbook—it’s to burn it.