These are specifically for wood floors, if you want carpet grippers, this is the wrong product for you.
As the instructions say to clean the rug where the grippers are to be installed, I used parcel tape to remove any loose material. And of course clean the floor where the rug is going to go.
Only time will time how long the rug will stay in place, and of course usage will vary: my rug is between my living room and kitchen, so a high traffic area. Even if I have to replace these grippers once a year: worth it. That rug moving around has been a constant bugbear!