Erlang begins and ends with Fault Tolerance.
Fault Tolerance is - formally! - baked into the very genes of Erlang/OTP - something that ends up being amazingly useful when you are building any kind of system. Remember, your clients (and co-workers!) will find new ways to break things, ways that you could never have imagined in your wildest dreams.
This, this is the reason to use Erlang. Once you get it, it completely changes the way you approach development, and you will find yourself writing "erlang" in whatever language you happen to be using (Mind you, writing tail-recursive code in java is a recipe for disaster, but thats another story…)
In this talk, I'll get into this buddha-nature of Erlang/OTP, pointing out how the various features of the language tie together into one seamless Fault Tolerant whole. It'll probably run 45 minutes or so, not counting questions…