Thread by @eric_seufert

I've heard people claim that using IDFV + IP Address will allow ad platforms to profile and target users as efficiently as they can now once the IDFA is deprecated. I dont think this is the case;.I'll explain why in this thread (1/X)

2/ First, a primer on IDFA deprecation and an explanation of the IDFV: mobiledevmemo.com/mobile-adverti…

3/ The IDFV + IP Address argument is: an ad platform will "see" IDFV + ip address combinations from apps a user has open in the background. If the time interval across which those combinations are polled is short enough (eg. 30 seconds), then changing IP address is mitigated

4/ The idea is: in real time the ad platform knows that this unique IDFV has this IP address from background app data, so if that IP address shows up in bid stream, it belongs to the IDFV from that app, and the ad platform has aggregated in-app data for that user in that app

5/ But IP addresses aren't unique. If I'm in an office with 99 other people, and a quarter of us are on iPhone 11 with the latest iOS version, then there's only a 1/25 chance that the IP address being seen is me

6/ But let's say its higher than that: a 50% chance the IP address is me specifically. Two problems: 1st, how does the ad platform have any knowledge of my spending habits? SDK networks could conceivable ingest IDFV-indexed in-app events, but why would developers pass them?

7/ 2nd: in-app purchasing is extremely rare. Across all apps, globally, maybe 5% of users make purchases? And app advertisers tend to run very tight margins on their ad spend. If I target the wrong user in the above scenario, there's only a 5% chance they'll monetize at all

8/ Which prompts the question: what is the benefit of the IDFA in the first place? It is that ad platforms can create IDFA-indexed device graphs via in-app event streams and profile spenders / engagers on a spectrum. Contextual targeting is also an option but is less efficient

9/ Put aside the question of IDFV-indexed event streams and assume every platform can do that (big, questionable assumption but not core to my point): how much lower can efficiency of IDFV+IP targeting be relative to IDFA-targeting and still outperform contextual?

10/ What's the average global IP overlap in that 30-second poll of IDFV+IP combos? Is it 25%? 50%? Are most ad impressions surfaced for people that are at the office with 100 other identical device specs, or are they surfaced for people at home with none other?

11/ And now one has to question: why did Facebook claim that FAN will be severely impaired by IDFA deprecation if they could simply use this IDFV+IP profiling method? If any company could execute this incredibly difficult technical feat, Facebook could.

12/ I've learned to never underestimate the ingenuity of ad tech companies. But my sense is that IDFV+IP address is being billed as a panacea by ad tech vendors because otherwise they'd need to acknowledge the immense damage that IDFA deprecation will inflict on their businesses.

13/ That said, I'm open to being wrong about this. Feedback welcome.