My wife, I, and some of our friends have also had this sort of gut feeling. However, I suspect it's a combination of selective memory (how many thousand random

My wife, I, and some of our friends have also had this sort of gut feeling. However, I suspect it's a combination of selective memory (how many thousand random things have been thrown at you by advertising/YouTube suggestions in the past couple months?) and data mining being scarily more effective than we suspect. Maybe the sorts of things or the pace of your web browsing early in the morning indicates grogginess. Maybe the machine learning has even picked up on some pattern like insomniacs clicking on a higher percentage of war and poverty news stories vs. celebrity gossip stories. It's also possible the ML has also used your browsing habits to pick up on the cause of your insomnia, while you think the advertising is due to your speaking about its symptoms. Also, there's a bandwidth/battery life tradeoff associated with 24/7 sophisticated voice conversation tracking. It would certainly take a lot of bandwidth to send everything to Google, and the amount of processing power to filter for conversations about thousands of potential advertising products is significantly more than just listening for "Hey Siri". This is especially true of the amount of semantic processing to know that, unlike 99% of the mentions of "Chad" in English (and maybe Romanian) conversation, "Chad" isn't referring to the dude down the hall who makes a mean quinoa ceviche. I would expect that the kind of sophisticated processing we're talking about would kill a phone battery pretty quickly, and offloading it to the cloud would cause operators to start complaining about the bandwidth usage. Though, I could be wrong. Edit: so, I think something spooky is going on, but I suspect that machine learning is sometimes just spookily accurate. I think it's Target that mixes in other coupons with baby product coupons when its ML has figured out a woman is 2 months ahead of giving birth, to make it seem less spooky.