If they really want to analyse the effectiveness of their ads...
...then they should take a look at how many times they pay to show an advert for something that has already been bought - often from the same place.
Advertisers on global ad network Facebook can now pinpoint exactly which devices and computers people use to buy stuff through online ads. "Facebook already offers targeting, delivery and conversion measurement across devices. With the new cross-device report, advertisers are now able to view the devices on which people see …
What they (and all online advertisers) don't track is how many serious / capable potential buyers are put off big-time by being tracked, spied upon, manipulated.
The most significant effect such practices have is to tell me which sellers to avoid.
The ones that treat me with respect (don't track / advertise at) but still provide good quality / real service are the ones I'm most likely to buy from / talk about.
This is a message that all sellers of actual goods / services would do well to heed and all sellers of advertising (smoke-and-mirrors trade) would wish them not to.
Even in the unual even I click on any served ad (facebook or otherwise) I rarely buy at that point (in fact I can recall ever having done so). Generally I'll go back to the internet directly to the site.
Without even more creepy behavior tracking they are only really going to get information on people who buy products and services immediately via their ad based click chain. (or mugs as I like to call them)
So much focus on making facebook more creepy while losing track of the big picture of the fact there are real people out there not just facebookers (maybe facebook should link up with a payment provider just to fill the last hole in their dragnet for their marks)
So I'm on my mobile, I click on an ad from facebook for a penis pump, or whatever. But don't buy it.
Then I log onto my desktop, and buy said item. How does facebook know that it's me both times? I'm on a different network, different device, etc. Unless they're reliant on me opening facebook on my desktop, finding the same advert and clicking through again.
Remember the trick here is really building a catalogue of associated devices.
You could associate the devices using a number of techniques:
* IP (when using WiFi at home your mobile will have same IP as your desktop)
* Geolocation (your mobile and desktop are in the same location in the evening)
* Account (same account on multiple devices) - could also come from 'partners'
...so devices which appear in all three of those techniques would be good candidates for being owned and operated by the same entity.
"* IP (when using WiFi at home your mobile will have same IP as your desktop)"
As will everybody else's in the household, so they have no idea if an add linked to a sale.
"* Geolocation (your mobile and desktop are in the same location in the evening)"
I've never seen anything that gets my PC location right. They usually show my ISP location.
"* Account (same account on multiple devices) - could also come from 'partners'"
I'm glad I make sure not to have the same accounts for different devices. And to use a different signup ID and email for everybody I do business with.
I used to feel slightly guilty about blocking advertising and anything else like that. But between tracking like this, and video adverts that download and play without me wanting them to they have so abused it that I feel I am forced to. They have spoiled it for those sites doing ethical advertising, because I can no longer trust anyone.
But it's services like these that keep Facebook free
Please don't aid this misleading of the public.
Facebook and Google are paid for by one in one of the most expensive ways possible for an individual: personal details. That is actually a very high price to pay, because you will be paying that forever. You can stop paying money, but you cannot change who you are.