Wouldn't this data be tainted by the fact that those deleting your cookies are the sort of people who actively adblock or protect their privacy, and hence are naturally unlikely to click on ads?
If the default for everyone was to not target users, the actual revenue value would probably be a wash, because ad targeting is useless.
Or perhaps without cookies, only lower value ads bid? There are a lot of factors and it's not clear how they interact or if they'd be relevant if cookies didn't exist for any user.
Perhaps, but many are using other privacy protection methods. Like I use Privacy Badger, which aims to largely leave ads but kill tracking cookies. I don't ever click ads though, so people like me are who fill out much of the "no cookie" market.
If everyone didn't have user tracking, the metrics on the effectiveness of stalking everyone would be very different.
If the default for everyone was to not target users, the actual revenue value would probably be a wash, because ad targeting is useless.