Most discussions of Internet privacy, for example Jaron Lanier Fixes the Internet, systematically elide the distinction between "my data" and "data about me". In doing so they systematically exaggerate the value of "my data".
The typical interaction that generates data about an Internet user involves two parties, a client and a server. Both parties know what happened (a link was clicked, a purchase was made, ...). This isn't "my data", it is data shared between the client ("me") and the server. The difference is that the server can aggregate the data from many interactions and, by doing so, create something sufficiently valuable that others will pay for it. The client ("my data") cannot.