None, and mean none of the coupon codes have worked. This is an attempt to get you to provide your "anonymous" information to google to further build out profiles. I would steer clear.

This extension has frequent updates, but its too bad I can't get it to do anything. I've gone to a handful of major shopping sites, gone to multiple items' detail pages, added to shopping carts, gone to checkout... Nowhere during the process does anything pop up, and nor does anything even happen when I click on the extension's icon. Their website looked promising. Oh well.