My theory is different from yours but only slightly. Companies have no use for recording your voice. 1. Audio streaming is expensive and requires lots of stora

My theory is different from yours but only slightly. Companies have no use for recording your voice. 1. Audio streaming is expensive and requires lots of storage, even if ephemeral, to be done widely. 2. Natural Language Parsing and transcription is fraught with errors. Go read your visual voicemail sometime. This, to me, is enough to close the book on this theory. What is entirely possible is this: Two individuals have a discussion. This discussion results is one of the individuals searching for a product in a store or online (some stores, like a famous hardware store) can detect proximity to certain items. If they can correlate interest based on a linked (or brokered) profile then they have ascertained that person A is engaged with said item. Targeted advertising is such that it is possible for you to be shown items based on your own interests, but it's also possible you're part of a larger network. Again, all a hypothesis and one hard to prove at that.