What online/multiplayer options would you find acceptable in a Sims game?

Multi-player isn't my thing, but as long as single-players can flag their accounts as such (so as not to be pestered with requests to join multi-player games) and it doesn't hamper the overall gaming experience for everyone, (no giving specific content to only one group or the other, able to add the multi-player feature without cutting corners in other areas of the game) I see no reason why we can't have both options.