Ginger Nuts are part of English history. Oreos are a recent North American import. I hear it said Oreos are cheaper than Ginger Nuts but do well in North America where they sell better. 'Do you know my Oreo does voiceovers',said one GingerNut to a A lister recently. I think it was an ad. It is good news that Oreos and GingerNuts mix to make good sales.
I might be wrong here,but North Americans have yet to taste a decent GingerNut,or don't know what a GingerNut is yet.
I think both biscuits would sell well in Canada given good promotion. I heard both Oreo and GingerNut sales here were doing well,but that the Oreo called time on the GingerNut missing Walmart. The GingerNut preferred Waitrose. Both biscuit sales are due to rise and make profits soon. FWIW Oprah likes both biscuits and drinks both tea and coffee,black and white!