Research in Motion ( RIMM) traded above $70 in early May; now it's below $50. This article seeks to accurately assess RIM's competitive position.First, the pluses. As I see it, RIM has three primary pluses in the market today: First, the vast majority of the world's handheld computer users do so on a pre-paid basis, unlike in the U.S. RIM offers its products on a pre-paid basis in many countries, unlike Apple and Google/Android. As long as the large majority of the world's consumers cannot buy iPhone or Android, RIM should do pretty well against its main competitor: Nokia ( NOK). Once Google ( GOOG) and Apple ( AAPL) decide to attack this lion's share of the world-wide market, RIM becomes vulnerable.