those saying you are already providing your information with other actions - credit card purchases, car location, phone location, etc..that is correct. but those are actual facts. What no one knows (and all those companies would love to know) is what are you thinking in your head. You paid $5 for coffee. what they don't know is - would you have paid $6 without actually going through the costs of raising the price and risking to lose you as a customer. same with
Amazon and Disney. You paid X for park tickets and Y for the hotel room. Would you have paid more? Did you just get a raise and promotion? these are the conversations that could be picked up that can be directly converted to you paying more anything that you buy/search online. Already flight ticket prices are customized based on your specific computer history/cookies/profile. another person looking at the same flight will be seeing a different price. Collecting verbal conversation, where you may say something that exposes your thinking or willingness to pay is worth lots of money to amazon, disney and others.