Caller Unknown


Campaigns, Content & Social
Captivating customers with a 9D audio thriller — Captivating customers with a 9D audio thriller — Captivating customers with a 9D audio thriller — Captivating customers with a 9D audio thriller — 

Captivating customers with a 9D audio thriller. How can immersive sound and cinematic storytelling thrill customers anew?

The dark, cold winter months were fast approaching, and the pandemic aggravated boredom and isolation. To strengthen loyalty among T-Mobile’s subscriber base, yet another campaign with ho-hum gifts or discounts just wasn’t enough.

We discovered that 47% of Dutch people listen to a podcast (source: Markteffect Podcast Monitor). So we decided to create an exclusive digital experience for T-Mobile to surprise its subscribers who were trapped at home. So we developed Beller Onbekend (Caller Unknown), a heart-pounding podcast where a random call turns into a nightmare. 

awards & recognitions
Image of a cellphone showing the landingpage of the "Beller onbekend" audio thriller book, and a second image of a scared woman biting her nails wearing pink headphones.

Amazingly lifelike, richly immersive 9D audio technology puts the listener in the midst of a gripping story, penned by by hit screenwriters Michael Leendertse and Thomas van der Ree (Ares, Feuten, Bankier van het Verzet and Vliegende Hollanders) and voiced by top-tier actors Monic Hendrickx, Victor Löw and Sergio Hasselbaink.

T-Mobile Caller Unknown

Caller Unknown was hosted on a special campaign page where listeners could win prizes by paying close attention to the twists and turns of the story. Inclusivity is a T-mobile priority, so we made an e-book version for hearing impaired customers.

"Beller onbekend" puzzle on a table next to a phone that shows a confirmation screen after submitting the answers to win a prize.

Subscribers were riveted. Caller Unknown helped T-Mobile significantly reduce churn, reducing service switchers and keeping customers loyal and engaged. Now that’s music to our ears.

Learn more
Does this sound like something for your brand? Ask Kim to tell you more.
Kim NieuwenhuijsCreative & Culture Director
We are code d'azur — We are code d'azur — We are code d'azur — We are code d'azur —