1) Every process in Erlang manages its own memory and has its own GC. This means that GC'ing one process will not stop the world.
2) Erlang has multicore compatibility baked in, through its process-based model.
3) Erlang enforces pure message-passing at a language level, so there is no shared state. This allows concurrent programs to be written much more easily than in languages where one has to manage shared state.
4) Referential transparency - to the programmer, one can use virtually the same code to pass a message on a remote Erlang process and an Erlang process on the same machine.
5) Fault-tolerant and self-healing mechanisms built in.
This is not an exhaustive list -- it just gives you an idea.