The other day I came across a headline where Facebook announced that they removed 3 billion fake accounts. It made me wonder whether advertisers were paying to show ads to those accounts.
My view is that the bubble is bursting from the side of the advertisers realizing the in/effectiveness of ads; and from the side of the "advertisees", people generally becoming aware that ads are a security/privacy issue, and ignoring or blocking them altogether.
Relative to the amount of data tracking (theft of privacy) that goes on, most ads are shockingly irrelevant. It's about time the bubble popped.