Twitter. Do you really think Selena (insta) is bigger than Katy (twitter)?
Exactly this. There may be a high amount of fake followers on Twitter, but most people with an account are actually old enough to buy albums and contribute to the success of an artist. As for Instagram, the same can't be said.
Any random person who takes half way decent selfies everyday can get a lot of followers on Instagram. Doesn't actually mean people care about them or their brand.
