I am sure there are many schemes in other countries.

In this case UK company Argos (aka Sainsbury's) after completion of on-line purchase they include a line offering cashback amounting to 16+ GBP = 19% cashback. Unless you read the URL it is not the same company. This one in "Walloon part of Belgium" or Luxembourg - I would guess from various "Sarl" & verbal clues.
So much for Brexshit cutting us off from the mother ship!!!!

Only when you have completed registration AND read the small print does it reveal they are happy to skim 15 GBP per month.

What they offer in exchange is a nebulous coterie of partners who will give access to more cashback of unspecified brilliance.

The Argos price beats E-Bay, for a branded item, funnily enough. Which is an infinitely better way to get my attention.