Also, couldn't a lot of it be done on device? Say, have a set of key phrases to listen for, and if the device hears them, then mark that the user should be targ

Also, couldn't a lot of it be done on device? Say, have a set of key phrases to listen for, and if the device hears them, then mark that the user should be targeted by certain kinds of ads. I don't have any evidence either way that that happens, but it seems like a more practical way to accomplish it.