Over in Toronto, plenty of restaurants and shops are finding things out about their customers - their habits, preferences and movements - reports the Wall Street Journal.
Turnstyle Solutions, a new Toronto-based company, has put sensors in around 200 businesses across the downtown are of the city, following signals given out from Wi-Fi-enabled smartphones to track people as they move about, then feeding information back to clients.
This enables the restaurant/shop to tailor its wares, food and marketing strategies to people they know visit or are nearby. It's one of several start-ups across the pond that's selling the service.
Unsurprisingly, this has been tried in London, but things grounded to a halt after groups kicked off about sensors being put in (of all places) City recycling bins.
Last August, the City of London Corporation asked Renew London to stop installing sensors.
The firm had fitted them in 12 bin "pods" - the ones that have LCD advertising screens in the sides - to gather up footfall information.
Trials were brought to an end after privacy campaign group Big Brother Watch flagged concerns.
The BBC was told by the chief executive of Renew London that the devices had only recorded "extremely limited, encrypted, aggregated and anonymised data".
Turnstyle's weekly report also feeds only aggregated numbers and doesn't include names.
However, it doesn't end there. The company also collects names, ages, genders and some other social media profile information when people are logged into Facebook on a free Wi-Fi service.
So it's obvious that location data is becoming more and more valuable to businesses - Turnstyle's success demonstrates that. But how much data is acceptable is another question.