Not sure how it is now, but back in the days it was a feature to have different hosts, as browsers would only ever open X connections per host. So if you spread

Not sure how it is now, but back in the days it was a feature to have different hosts, as browsers would only ever open X connections per host. So if you spread your assets over a.example.com, b.example.com etc. it could load faster than if everything came from the same place.