Katy has given Max Martin four 10 million sellers to date. Before Katy he never had a huge song (10 million+ sold). Why is his work with Katy the most successful? Does this prove Katy not only revived his career, but made him bigger than ever?
I Kissed A Girl: 10 million+
California Gurls: 10 million+
Roar: 12 million
Dark Horse: 10.5 million
Who else has done this?
Why are Roar and Dark Horse the biggest songs of his career?