Secure? Stable? Could you elaborate? Are all messages encrypted? Are other applications so terrible now-a-days that "doesn't crash!" is a feature? Other than that, it sounds like IRC, with a read notification for those who just need to know if their message hasn't been read yet, or they're being ignored.

I was reading the page looking for grandparent's question, and I still don't see why bbm would be such a huge feature that bb owners just can't live without. Sure, I can see how it may beat sms where international communication may be concerned, and texting someone in a different country doesn't work, and I can see how the group chat is useful, but every single other IM client can offer the same thing... I just don't get it.