art/ad where is the line

most artist would probably categorize advertising as not being art but some of the ads really do cross the line between art and just a straight forward ad. For example, several years ago BMW did a series of short films with big name directors and used them as online ads/short films. Are these films considered ads or creative film making?? Or both, can they even be both an ad and a creative film at the same time. I believe that the answer is yes ads can be creative and effective as a display of the product. That may be where the heart of the debate between ads art arts lies, because ads glorify a object does that destroy the artistic merit of the art or film making behind the ad??