Well that's why they are free. In exchange for a free browser, you give up some of your privacy so that the owner of the browser can determine your demographic and sell that data to advertisers so they can target ads at you.
This is why browsers are free.
I suppose an entrepreneur can come out with a browser that does not track you and charge $9.95 a month for the privilege. However, I do not think that would be successful. Everybody has come to expect that browsers are free.
+1