Conspire to control the galaxy!... I guess you already done that though!
Seriously though I would say, working together towards common Goals...
considering, SM is about building space stuff and then using / implementing what you have built, that the best activity is working out plans for builds and how to implement them... and of course actually build and implement it, i.e. build your SM universe.
boring rambles of a madman...
It may be necessary to define what a faction is or represents... and ask yourself, "what do you want to do most?" then try to find others that want to do different things, so that it all fits together and forms a "Faction", because tbh... a group of builders that only "mine and build" or a group that only PVPs all the time does not embody what a Faction actually represents: "
people with different roles working together towards common goals".
Roles...(insert stuff here)
I guess this all takes the game towards RP, but it is a "space sim" in many ways after all, so in a respect, even the "non-RPers" are roleplaying.
Considering there are 4096 sektors in a single system, there is really alot to do in SM, populating your Faction territory for starters.
Unfortunately many only build a few stations and a shipyard, which are never completed.
To round this up quickly I am going to say that the biggest "WOW" factor ingame is: "Cool-Space-Stuff", i.e. "Eye-Candy".
Realistic looking Space Stuff is überCool! ^^
On that note I will leave off on "build your SM universe", together!
Smallprint:
An active administration working together with the player-base would of course be a big help making it a reality on public servers... new NPC factions, Gallactic Law etc...
But this is a big debate that needs a seperate thread... bad Admin etc...