I once asked the head of the monster munch factory near durham why they stopped roast beef flavour, as they were the best ones. He replied that their market research showed that no one liked the roast beef. Never mind that the sales of roast beef flavour would be so low because supermarkets insisted on selling only the pickled onion flavour. Anyway, a few years on, and roast beef is back. I assume he or his market researchers got the sack.