Altruism and nostalgia continue to feature in some of the advertising campaigns of Britain’s biggest retailers at this time of comfort and joy. But something obvious is missing – and that’s down to some little-known rules and Adland’s own inhibitions The other day I received an invitation to a birthday party on 27 December. Guests are encouraged to come along and enjoy “convivial conversation and yet more conspicuous consumption”. Sent by a Catholic I see every week at Mass, it made me chuckle with its resigned acceptance of the fact that, for a great many people, conspicuous consumption is what Christmas is all about. This view is unavoidable, and to some extent understandable. The little bookshop where I have worked for years barely ticks over for mo