In my four years of RP.. I've done quite a lot of different types. A lot of people like to make one that has a plot to it, not just a couple together for a date or something. Where I have RPd I've participated in chats that have been solely wars for a couple of days or more. Generally the Mass RPs they call them.
There could be a reason they get meet etc. Or they get asked to help with some government thing and meet then. My mind is ALWAYS full of ideas. Especially since I enjoy the ideas involving Ancient Empires.