Blue Cross Sale. This is primarily a United Kingdom retailing device for signifying a day of further reductions in the sale prices already on offer. It is usually marked by signs throughout the store showing a large blue cross, the words "Blue Cross Sale", and indicating the percentage by which the sale prices are further reduced. On occasions it is advertised as "Blue Cross Day" but it is, in fact, not always strictly limited to just the one day! This device was first introduced in 1970 in the then Lewis's Department Stores, and was originally the idea of Peter Wiard, the company's Chief Accountant. It was introduced to reduce the inordinate time taken by staff re-marking all the individual sale tickets by the requisite percentage, in time for the following day's opening time. Drawing of a self-service store. ... In marketing, sales promotion is one of the four aspects of promotion. ...