This extension (Honey) runs in the backgound o my commuter when I am on-line, When we make a purchase, no matter which browser we are using, it finds us a better deal, if one is available. If not we get some cash back.
It;s free and does not slow the system down. It does not seem to report to Mark Z ot Bezos or either of the political parties.
Pretty much a win for me.