Okay, but wasn't this expected ?
We all hate ads, but what did we expect ? That some rando will pay for all those server and personnel bills out of the goodness of his "heart" ? Please. I wish the culture of Silicon valley wasn't so full of bullshit that this'd have become obvious a long time back.
(For a more egregious eg. of ads, look at LINE which is all the rage in Japan. Or indeed Google, whose entire Android/Chrome business is made to subtly feed data back into its ads business).