A few questions though: Is there just one F2P server? I didn't see an option to pick one. If so, is it separate from the premium people? From what I gather most of you still have pay accounts.
Unlike other MMOs, Cryptic tends to heavily utilize instancing technology so there is only one server shared by both premium and f2p players. Additional instances are spawned when current instances are filled (usually ~50 players per zone-instance, and chat works across all zone-instances).
I'm not really sure about the terms they are using but, I assume that there is a server farm that is clustered into one server (shard). That server is then virtualized into several virtual servers (instances). I use clusters and virtual servers but I'm not familiar with the terms shard and instance. Someone smarter than me may know.
That is exactly it.
An instance though is a copy of a specific map, say spacedock, where players will be automatically routed to as long as there is room. It can go up to 75 players atm I believe.
When the instance is full another copy of that map is created and more players will be routed there.this is an open instance where players can interact doing different things.
A prome example is the mythical Deferi invasion map where different objects appear interactible to players depending on their mission status.
The majority of missions happens on closed instances that is specifically created for one player. You can join another players instance if you are teamed with him. On sone missions you have to be on the same mission steps or level to join him.
Bur at all times you can interact with every player in the game at least per chat.