Scalability is a frequently-claimed attribute of multiprocessor systems. While the basic notion is intuitive, scalability has no generally-accepted definition. For this reason, current use of the term adds more to marketing potential than technical insight.In this paper, I first examine formal definitions of scalability, but I fail to lind a useful, rigorous definition of it . I then question whether scalability is useful and conclude by challenging the technical community to either (1) rigorously define scalability or (2) stop using it to describe systems.