The economic crisis suffered in Spain in the last ten years has forced management of the country's public museums to look for new sources of funding with which to compensate the reduction of public funding. Business sponsoring has been one of the most intensely studied channels. One of the consequences of the new scenario is the weak bargaining position of museums before sponsors. There are clues that suggest that a new model has arrived in Spain: museums are used as public relations agencies by businesses and the subtlety that once characterised the relationship between a sponsored museum and its sponsor disappears. The article lays out the development of business sponsorship in public museums in Spain, illustrating the changes that have taken place in this relationship. Through a content analysis of cases that answer to the new model and structured interviews with cultural journalists from written media, it is shown that sponsors do not achieve their objective, which is to factor the communication media into the equation to increase their brand notoriety and/or strengthen their corporate image.