I think that the idea of these novel drinks is that it's good for manufacturers to keep their R&D staff busy, and even if they will probably be unsuccessful in a crowded drinks market where people often buy the same drinks out of habit, a successful drink will be very profitable. So manufacturers keep making them, the coke affectionados, etc., buy them and interest is generated in the produce, so the manufacturers don't lose much money and they might just get lucky by finding a winning product. I'm sure coffee-flavoured coke was such a product.