Granted, one can easily envision some new type of app on the iPhone, Google's ( GOOG) Android or Microsoft's ( MSFT) Windows Mobile that will mimic BBM more closely, or utilize some entirely new technique, to achieve the goal met by today's BBM. Perhaps one or more such apps already exist, and simply haven't obtained meaningful publicity yet. So far, however, the awareness for the privacy-concerned A-listers remains with RIM's BBM. Given how small a constituency this is, it is hardly going to make a numeric dent in and of itself as RIM continues to lose market share in the U.S. That said, as Vladmir Lenin stated in 1922, it never hurts to "capture the commanding heights" of the economy . There is one more question about Apple's iMessage product that I have found to remain somewhat unanswered: How do you know before you send a message to someone that it will do so over iMessage instead of SMS? I know that conversations are color-coded once you get started, letting you know whether you're on iMessage or SMS, but what about if you want to rid yourself of SMS altogether and just stay with iMessage? How do you prevent iMessage from not causing an expensive SMS to be sent or received when you really want to be using a free iMessage? This is particularly important if you're abroad or exchanging messages with people who are using foreign phone numbers, because those kinds of SMS are even more dramatically expensive. I imagine this will clarify and improve over time, and I would like to hear from people with theories on this. RIM has huge problems in the U.S. in particular -- although growth remains strong internationally with 67% growth in the last quarter -- and iMessage won't help RIM going forward. That said, iMessage doesn't fit everyone's bill and has some unanswered questions. At the time of publication, Wahlman was long AAPL, GOOG and RIMM.