As you continue to use their services you are shown ads or use services other companies have paid to have linked to. Even when things seem “free” they are never free. Google Maps makes money off charging their API for businesses. They charge what they do because their data quality is high. Their data quality is high because they track usage as well as ask users to improve their data (like ask if a restaurant has table service). Every time you search for a business or call a business because a Google search that gets tracked and compared. Businesses can also pay to appear higher in advertised search rankings.
TL;DR: You are given free access to improve Google’s data and they sell off that improved data to companies, or charge for higher visibility to their potential customers.
Pretty sure that’s exactly what the other guy said… “Selling” your data can be worth it if you get good service in return, which is what Google used to provide, but now it barely works half the time.
Maybe I misunderstood the point of data, but I was making the point that they don’t need to perform complex tracking or rely on non-anonymized data. Invading privacy isn’t a very important part of their business model. People still freely feed them data either directly (captcha with OCR scan or Street View images; adding location reviews, photos, and details; YouTube likes and subscriptions) or indirectly (searches and links you click after; YouTube views; places you navigate to and what time; your location when you request navigation directions).
The tagging of data around specific people (privacy) which the EU is very concerned about, I feel, is grossly overemphasized. Just counters on what gets pinged and when on a transactional basis is very much good enough for Google’s business model.
