many ISPs over here offer a ~5-10% discount on monthly bills if you agree to have your traffic analysed for marketing purposes. the last time I signed a contract I had to explicitly opt out of that. the ISP providing internet to all of my landlord's flats offers a similar deal when signing a contract, and 1. I'm willing to bet that my landlord has opted in, and 2. I have no way of opting out of that for my flat. I think I'll stick with a VPN for the foreseeable future.