Bieber is probably best known to those over the age of 20 as a name that pops up frequently on Twitter, but his personal appearances across the world draw thousands of ardent fans.
He is described as the first pop star to come to fame via YouTube – a recording of himself he posted on the site was discovered by Snoop Dogg's agent, who subsequently signed the teenager.
Now he has made a video promoting Proactiv, which encourages teenagers to prevent acne with a three-step cleansing and moisturising routine.
Bieber delivered some words of wisdom to his fans, saying: "I know that for a teenager, it doesn't matter how many people are looking at you, you don't want acne on your face."
The singer's deal with Proactiv will also raise awareness for an educational charity he supports called Pencils of Promise, an organisation that builds schools in underprivileged communities globally.
Proactiv has a history of using celebrities to endorse its products. Those who have backed the brand include Katy Perry, Delta Goodrem and Mandy Moore. The products retail in the UK for £39.50 and are sold online.