As I mentioned in another thread, I'm not interested in platform-specific messaging, since messaging itself isn't a platform-specific activity. But I'm also not interested in cajoling people to use a specific tool. Consequently, I use WhatsApp and FB Messenger for everything. I almost never use BBM. Like others, I'm disappointed to see it become adware, just on general principles, but it doesn't affect my usage patterns, which are close to zero anyway.
WhatsApp now has a web app that works at least as well as BlackBerry Blend, if not better. I find it very handy when in the office, although it makes me feel that we have come full circle from the day when AIM was the cross-platform, device-neutral messaging leader. AIM is still out there. Why doesn't anybody use it anymore?