As technology has become more advanced, mediums and content are slowly starting to merge and cross over. For instance, Uber is an application that can only be used on a cell phone, which can be seen as another medium. In this sense, Uber could be considered as the content of the cell phone. However, according to McLuhan's definition of media, which includes all technology, Uber can be seen as its own medium. Therefore, McLuhan's tetrad's lack of focus can potentially be problematic as more and more mediums have content, and that content can also be considered as its own medium.