[mikeash]

It’s always hilarious to look at ads and try to figure out why they think I’m the right audience for them.

Facebook keeps showing me ads for a cup with a hidden compartment for alcohol in the lid, and for various gun safes. Apparently they’ve decided I’m an alcoholic who attends a lot of festivals, and a gun owner. Neither one is remotely correct.

The other day a different site showed me an ad for a capsule containing a 360° panoramic camera that a proctologist can use to inspect people’s digestive tracts. I’m not any sort of doctor.

It would be one thing if all this abusive technology was used to show me relevant stuff. But they do all this nonsense and end up showing me ads for butt cameras?!

[srrr]

Facebook will always show you an ad. First the system tries to select a relevant ad with the highest predicted income ($$$) for FB winning the auction for your screenspace (the placement). If FB can't find a perfectly relevant ad the algorithm will choose a less relevant ad, But it will always show you an ad.

The thing is FB does not select a relevant ad from all available ads on FB, but only from a subset of ads matching a certain targeting setting that in turn matches your profile or interest. And this targeting setting is set by the uploader of the ad. And in some cases advertisers select a targeting that does not make any sense at all. (They target you by error.)

Does the placement algorithm like to show you a non relevant ad? Most likely not because on average it yields less money for FB. It could be that FB does not have much information on your interests or your privacy settings disallow using this information and the algorithm does not know what is relevant to you. And/Or the advertiser had a very high bid for the placement and the placement algorithm decided a less relevant ad with a high bid yields more money than a more relevant ad with a low bid.

(This is often the case if the advertiser decided to pay per ad-view and not per ad-click. Pay-per-click ads only yield money to FB if they are relevant, because users don't click on non relevant ads. Per-per-view ads always yield money for FB.)

But in the end it's not facebook who is to blame. It's the advertiser setting up stupid targeting and placement bids. (I once burned through 10000€ in one minute because of an erroneous targeting setting while showing the right advertisement to the wrong people...)

[manigandham]

Most ads are not that targeted. That's a fallacy that seems to come up on HN but the reality is that most ads you see are generic large buys across very wide populations. Targeting costs more and the increased acquisition costs don't always pay off for every product. Also most ad systems will always fallback to show you an ad no matter how lacking the targeting is, because a filled ad slot is better than an empty one.

[mikeash]

It doesn’t much matter to me whether it’s badly targeted or untargeted. At the end of the day the result is the same: they pour all this effort into abusive tracking and then it doesn’t even achieve the result that’s supposed to be the reason they do it.

[manigandham]

It doesn't achieve it because it's not used. They cant control what advertisers do with their campaigns.

[dorfsmay]

I'm surprised Facebook's showing irrelevant ads to you. The few times I have to use Facebook the ads are so relevant that it is downright creepy. They are known for buying people purchase history from credit card company, but they are still stuff I have not figured out how they made the connection, for example, I get ads for very specific product that family members with a different last name and who don't have facebook, bought recently.

[T1glober]

It gets really spooky when you start getting ads for something that was mentioned a couple times in Messenger. Wouldn't be surprised if they are scraping DMs now, too.

[afiori]

And the alternative explanation is even worse: modern behavioral model (at times) as so good that they know what product to sell you before you do.

[clinta]

The ads I get from Facebook have gotten much more generic and less creepy after I started using Firefox with the Facebook container plugin.

[scarejunba]

That's the low quality untargeted ad each time.