I think that organizations can have several cult characteristics without technically being a cult. There are large corporations which have had certain characteristics of an organized crime ring, without technically being on. However, it all depends upon one's definition of the word cult.
I think that the two vital aspects that a group must have to be a true "cult" is for the members to be physically or geographically removed or separated from society at large (i.e. Jonestown, Heavens Gate, Branch Dividians, Moonies, etc).
Also, I think that a group must demonstrate a clear pattern of financial exploitation where members come to rely upon the group and leadership for physical needs.
There are other groups that are labeled "cults" which do not demonstrate these characteristics: The Mormons, Seventh Day Adventists, Freemasons, and others.