I first got the BBM around four and a half years ago with my first bbm however as i was one of the first amongst my friends to get a bb it was not the most useful of communication tools. As the bb became more popular i seemed to find that i used it a lot more. It's very useful for those who do not get unlimited texts as it is free however the obvious limitation is that it is only available to use with other blackberry's. The ease of use varies between bbs however the use of the smiles and also ease of adding pictures videos and music into the conversation makes for a very useful application with the added bonus of telling you when the message has been delivered and also read. (Helps in deciding if people are avoiding you) On top of all this there is the obvious advantage that there is no initial cost in buying bbm as it is completely free from the app world.