I personally have been calling for Research in Motion to take BBM cross platform since March of 2011.

Although rumors pointing to such a move are pretty easy to find, BlackBerry Messenger, what I believe to be the best mobile IM client of all time, is still only available on BlackBerry devices, and, sadly, has a shrinking potential user base.

Former BBMers, like myself, would return to using BBM on our non-BlackBerry OS smartphone operating systems in a heartbeat, if it were available, but the truth of the matter is that the longer you go without using BBM, the less you long for it.

A bigger problem for RIM is that BBM, though still insanely popular among BlackBerry users, is being challenged by popular third party IM clients, not because they are better than BBM, but, because they allow you to more effectively communicate.

BBM is a tool built for communication, but, is limited by the number BlackBerry using contacts one has, which sadly, is a dwindling number.

Cross platform mobile IM clients like WhatsApp Messenger, on the other hand, are limited by the number of one’s contacts that use smartphones and are willing to install the app.

Seeing how WhatsApp is the second most popular app on the BlackBerry, trailing only BBM, one can infer that the number of people willing to install it is pretty high.

The number one reason RIM should take BBM cross platform is because doing so is necessary for the app to remain relevant

This is my opinion, and, I love to hear yours in the comments…