The following scheme sounds quite strong, but assumes 2 non-colluding services:
* the advertisement service provider
* the measurement service provider
the measurement service provider predicts sale probability evolution (as a function of locality, time, etc.) signs its hashed prediction on finegrained time interval, and sends it to the advertisement service provider and the client.
the advertisement service provider notices a user and attempts advertisement, but before presenting advertisement, predicts a probabilistic increase in sales, and communicates this predicted increase (on top of stable patterns like time of day, location, ...) to both the measurement service provider as well as the client.
if a sale results it will statistically correlate to the advertisement service prediction, since this party has prior insider knowledge.
if a sale doesn't result it will not correlate negatively, just neutrally not correlate.
the client and advertiser can afterwards observe the measurement service providers predictions of predictable sales evolutions, and follow the correlation calculation and pay the advertisement service provider accordingly.
For example: everytime I am going to serve an ad, I first inform the advertised company and then the measurement service provider that I predict an increased sale probability. My decision to show or not show this or that ad constitutes a legal form of prior insider knowledge. Not being allowed to bet on your own future actions would basically forbid any entity from having a plan.
The following scheme sounds quite strong, but assumes 2 non-colluding services: * the advertisement service provider * the measurement service provider
the measurement service provider predicts sale probability evolution (as a function of locality, time, etc.) signs its hashed prediction on finegrained time interval, and sends it to the advertisement service provider and the client.
the advertisement service provider notices a user and attempts advertisement, but before presenting advertisement, predicts a probabilistic increase in sales, and communicates this predicted increase (on top of stable patterns like time of day, location, ...) to both the measurement service provider as well as the client.
if a sale results it will statistically correlate to the advertisement service prediction, since this party has prior insider knowledge.
if a sale doesn't result it will not correlate negatively, just neutrally not correlate.
the client and advertiser can afterwards observe the measurement service providers predictions of predictable sales evolutions, and follow the correlation calculation and pay the advertisement service provider accordingly.
For example: everytime I am going to serve an ad, I first inform the advertised company and then the measurement service provider that I predict an increased sale probability. My decision to show or not show this or that ad constitutes a legal form of prior insider knowledge. Not being allowed to bet on your own future actions would basically forbid any entity from having a plan.