There's a good rule about this "if you aren't paying for it, then you are the product". That's certainly true for google, and facebook. Strava is different, even if you aren't paying for it, you are still the customer - they want you to upgrade to premium. There are no ads, because the entire app is an ad for strava premium. And I think they are doing pretty well out of it. I just looked at the leader board for CC on strava, and 4 out of the top 10 are premium users. That suggests that in the UK, they are getting an average of £16/year from heavy users (and light users don't tax the system that much, so it doesn't matter if they are paying or not). That's way more than they would get from pitching 3rd party ads at us or selling the data, so I expect they won't be doing anything with the data the users won't like. Selling anonymised heatmaps seems in everyone's best interest so they are probably doing that - but their main source of revenue is premium users.