Today, Brian challenges folks to design a quest around an area which requires significant player investment to access. If the player had to work to reach the area, there had better be something worth going there for.
I suggested going with a faction reward. One of the NPCs in the more accessible gameworld is connected somehow with one or more of the NPCs in this offset area. By coming back to the mainland NPC with evidence of the meeting, the player would have a new faction standing only possible that way. It's not just the next leg of a questline. It's a faction relationship with ongoing benefits (quests, further networking opportunities, gear, etc)... benefits which can be added to or modified by developers at any time.
It occurred to me that what I was suggesting is a non-linear NPC relationship.
In current MMOs (and games in general), factions appear almost exclusively as ladders. They're linear. "Finish this job, and I'll give you the next one." or "Finish this job, and you'll be promoted (so I can give you the next job)." A few single-player games, like Deus Ex, offered branching questlines; the player could choose which branch to follow. But even those were basic; essentially about progression from StepA to StepB.
Another possibility is realistic networking. Networking reaches out, not just up. In a game that's less about levelling than about exploring and experiencing, ala Star Wars: Galaxies, networking is a viable and more engaging form of faction gameplay.
Let's use a Star Wars universe for an example. Hans Solo (a smuggler) knows Lando (a mine owner), Luke (a jedi) and Leia (a princess and military official). They're all bigshots, right? They're people with a lot of power or influence. But Hans and Lando probably also know some mechanics and small-time smugglers. Luke grew up on a farm, so he could point you to some farmer friends and maybe have some trading pull with the Jawas near his hometown. Leia... well, ok, so maybe Leia only knows important people.
The point is that those connections back to people of lesser power and fame can be just as valuable at times, even when you're discounting personalities.
And, perhaps more importantly, connections are personal. Players would take more interest in the NPCs they interacted with if they knew that not every other player (or every other player of their particular class) had the same relationships. It certainly takes more planning from developers, but more intricate NPC relationships could offer replayability and customization.
Maybe my character has strong relationships with a lot of rough and shady NPCs, while your character flirts with various NPCs with political interests (large and small). As I've suggested somewhere before, one player's faction can temporarily influence the group's faction. If my character's in good standing with Joe Roughneck and you have neutral faction with him, then he'll be somewhat amenable to you as long as you're grouped with me. On the other hand, if you stole Joe's money purse just last week, then Joe might not speak a word to me as long as you're around.
And, of course, faction doesn't have to take the form of an on/off switch. It doesn't have to be as simple as "Good faction = offer the player a quest / Bad faction = be rude and send the player away". Neverwinter Nights had NPCs which acknowledge more graded differences, like intelligence and appearance. Rewards can be as simple as different dialogue options, but they can go further.
If players had truly individual sets of relationships with NPCs, and one player's network of NPC ties could affect another player's gameplay, faction gameplay would be more fun and worthwhile.