This post is posed as the next big step in internet pricing, not something necessarily happening today.
Today, it’s not standard procedure outside of some specific segments (that I know of, maybe airfare? But the data fed in is more limited) but tapping into the vast amounts of data we leak through the services we use is far too big of a gold mine for companies to overlook researching and tapping into. There’s a lot of things that need to happen (who supplies data? Google is the hypothetical here but what’s their price? etc.) but it’s absolutely feasible at scale.
Google isn’t necessarily the seller, but Best Buy, Staples, Amazon, Walmart and Target could hash out a deal with Google (or Bing, etc.) for “insights”.