Does an adds date have that much effect? Or does it depend on how strong the song is?
It won't have any effect. It will be much higher than 40 already when it gets sent to radio. Probably already on more than half of the stations already
It will definitely have some effect. Capitol has this all timed and that's the official green light.
if it's already played on almost every station, an adds date will literally have zero effect
Dark Horse's adds date had no effect either cuz it was almost top 30 already I believe
just imagine the updates after adds day 
Congrats Demi 
Destroy them, Katy.
