My dad always bought the no-name cookies for us, according to him every major brand had a deal with discount supermarkets to sell their brand name product under a cheaper no-name alias.
That might be true in some cases but the stuff he bought was mostly just cheap knock-offs that didn't even come close to the original.
This is true for household appliances, rather than letting the factories go idle during slow sales they pump out the same machine under "generic" brand names. QC isn't as stringent I suppose.