[JAlexoid]

I would have thought that HN readers would at least be somewhat tech savvy, but alas.

Advertisement systems are way less advanced and much more stereotype driven, than privacy freaks care to acknowledge. Think of this - advertisers have less than 100ms to decide the best ad to show you... often multiple times per website. Do you really think that any ads are actually personalised?

I remember having to differentiate between Bike Helmet for Barbie(a toy) and Barbie Bike Helmet(safety device for children)... Or the fact that if you let a learning algo run through the categories, they can place dildos(adult toys) right next to water guns(kids toys).

There are services that target you with offers that are highly tailored*, but online ads are not one of those services.

(Amazon's "You May also like", food delivery services suggestions, and similar things that can calculate for a long time)

[andrepd]

?? 100ms? Why, is precomputing outlawed or anything and I didn't hear it? And "privacy freaks", really? I thought after Snowden the notion that only crazies care about privacy no longer flies as it did.

[JAlexoid]

I'm not interested in educating you of all the constraints that each display ad tech company has to operate with. Suffice to say - no one is calculating or storing a list of "perfect ads" for you, nor does anyone particularly care that you like tentacle porn. You're really not that valuable.

Yes. Privacy freaks are overreacting on how deep ad tech cares to know about you. It's way less than what NSA or spying agencies(hello Facebook) are able to collect and use.

[rightbyte]

100ms? I mean Google et al. can precompile a list to serve you. There is no need for a hurry.

[JAlexoid]

They can't. The lists of viable ads are constructed, built and updated real time. There are shortcuts, but then you have to account for things such as quality scores, probability of you clicking on the ad if you recently have seen them, etc.... and do that trillion times per second.

Even light speed is not infinite.