Have we reached peak hipster? I've just been sent an advertisement for a beard brush - right-handed model.— Robin Wilton (@futureidentity) April 1, 2016
The ads I get are mostly really poorly targeted; am I doing #privacy right, or is the industry just not very good at it?#CISNOLA— Robin Wilton (@futureidentity) June 7, 2016
This kind of thing in my TL gives me faith that targeted advertising algorithms still suck. https://t.co/JOkuybTXNn— Robin Wilton (@futureidentity) March 3, 2018
But when I read his latest tweet, I thought of the exception that proves the rule. Fowler defines five uses of this phrase; I'm going to use two of them.
Firstly, when an advert is exceptionally badly targeted, we notice it precisely because it is an outlier - an exception to the normal pattern or rule. Thus reinforcing our belief in the normal pattern - the idea that many if not most messages nowadays are moderately well targeted. This is what Fowler calls the "loose rhetorical sense" of the phrase.
Secondly, adverts aren't necessarily misdirected by accident. Conjurers and politicians use misdirection as a form of deception, to distract the audience's attention from what they are really doing. (Some commentators regard the 45th US President as a master of misdirection.)
This is how Target does it, so the pregnant customer doesn't feel she's being stalked.
"Then we started mixing in all these ads for things we knew pregnant women would never buy, so the baby ads looked random. We’d put an ad for a lawn mower next to diapers. We’d put a coupon for wineglasses next to infant clothes. That way, it looked like all the products were chosen by chance." (Forbes)
So just because a marketing message appears to be a random error, that doesn't mean it is. Further investigation might reveal it to be carefully designed to foster exactly that illusion in a specific recipient. And if it turns out to be targeted after all, this would be what Fowler calls "the secondary rather complicated scientific sense" of the phrase.
85 million faces (Oct 2016)
Charles Duhigg, How companies learn your secrets (New York Times, 16 Feb 2012)
Kashmir Hill, How Target Figured Out A Teen Girl Was Pregnant Before Her Father Did (Forbes, 16 Feb 2012)
Wikipedia: Exception that proves the rule, Misdirection (magic)