You’re looking at this from a point where the only piece of information about you out there is the data collected by the roomba. In reality, every sensible data broker would just add that signal to your already verbose profile and feed it to a model to determine the stuff you’re likely to buy… or would trigger you to generate engagement or whatever is needed.

The privacy danger here is not the one data point, it’s the unknown amount of other parties who will mix and match it with more data.

With GDPR, I’ve been requesting copies of my telemetry from various corps and it’s amazing the kind of stuff they collect. Did you know kindle records very time you tap on the screen (even outside buttons), in addition to what you read and highlight and pages you spend time on? Now add to that your smart tv’s insights about you and your robot vacuum cleaner … you see now this all grows out of control.