i understand that's how ads are sold, but it does doesn't work.
the numbers are inaccurate, varying wildly depending on how you measure it (web server logs, analytics, etc), and its a horrible way for advertiser to measure ROI.
i don't think it's horrible, it's just not the only way.
"display advertising" isn't going away. just because someone doesn't click on something (or otherwise 'engage') at the moment of viewing doesn't mean that it was wasted. People remember stuff, and often won't act until they see something 8-10 times.
Just because there are other ways of measuring doesn't mean that using 'impressions' to gauge ROI is 'horrible'.