GameSpy: Here's what happens in an online shooter. You boot up the game and join a match. Shoot 12 enemy soldiers in the head. Die 15 times, despite your best effort. Check out the stats in the post-match debriefing. See that your team edged out the opposing team in kills anyway. Send a "GG" or engage in trash talk, depending. Close the game.
But here's what doesn't happen: Feeling satisfied that you've spent half an hour securing a crucial planetary installation that supports a distant friend who pilots a fearsome battle cruiser, a pilot who then happily escorts you and your fellow mercenaries to the next planet in your expanding empire in need of grunt labor. Coordinating that in-game, or perhaps over email or Skype -- however you keep in touch with allies. Needing to, because the band of thugs that tried to infiltrate your planet now carries a vendetta against your entire corporation, in all likelihood.