Okay, there's some chatter about replay these days. Some people think it's absolutely critical, others think it's either totally irrelevant or even a waste of effort.
Me, I float in the middle.
When you design a game, one of the things you need to keep in mind is an "efficient" use of your audience. Basically, you want to impress your audience, get your audience dedicated, get your audience evangelizing, and get your audience to pay you.
Lets say we write a fifteen hour game, selling it over the internet for $14.99.
Let's skip all the other stuff and go to the heart of the matter: getting a dedicated audience. Dedication really drives everything else. Dedicated fans will evangelize, spend money, and be impressed.
Dedication is largely a function of how much time you can convince someone to spend in your world. In this case, our game is fifteen hours long. So, we get a certain amount of dedication out of that: let's say it's 15 * Q, where Q is our Quality.
The thing is, Q also determines how long people want to play the game. So, if our Q is low enough that they only want to play for five hours, then we're wasting our time developing fifteen hours of game. The additional ten hours not only aren't necessary, they actually decrease the amount of dedication players will feel because they won't get to see our cool endgame - no closure. All the player remembers is that he didn't manage to get through the game.
On the other hand, if our Q is high enough that they want to play for 40 hours, then our 15 hours of gameplay simply aren't enough! We're not being as efficient as we could be.
There's three solutions to that.
1) Episodes. Release new content. Have them pay for it. This will probably work, but I question how well for reasons I'll explain shortly.
2) Player content. Allowing players to generate content, whether in-game or simply fanfiction, radically increases the amount of play time players can spend in the game. Of course, this has a lot of other benefits and problems, and is really a book on its own.
3) Replay value. Allow people to replay your 15 hour game several times, each time having fun.
Here's the thing: people don't react the same way to the same game. For one person, they might want to play your game for 80 hours. Another person might only want to play it 10 hours.
With episodic content, the people who only want to play 10 hours aren't going to buy additional episodes because they are played out. Or, worse, they'll buy the episode not realizing that they're played out and think that it's "boring". Additional episodes would have to be very different games in order to draw these people back in.
With replay content, however, people can choose how much they want to play.
"Isn't that inefficient? Can't you get more money by using an episodic system? Sure, you'll lose some players, but the rest..."
It's a tough question. First, episodes cost a whole lot more on a per-hour basis than adding replay value. So, you're spending a whole lot more money and probably falling behind your demand. You've got to worry about players drifting away and forgetting about you.
Second, having a significant portion of your audience going, "yeah, I played the first two episodes, but it got kind of boring" is pretty damning. It's probably going to rather painfully limit your mass appeal if that kind of opinion is common.
Third, hardcore players who play your one game with high replay value for a hundred hours will be just as zealous about selling your next game (be it an episode or an unrelated event) as players who play through seven fifteen-hour episodes.
How this balances out, I'm not sure. Is it worth going episodic and trying for extra money? I think, if you do, you'll have to try for a high-quality game where each episode has new gameplay and a decent replay value.
The other half of the equation is "what can we do to increase the replay value of our game"?
I'll post about that in a few minutes. Or, probably, you just read it, since these things display backwards. My opinion might surprise you. Unless, of course, you've already read it.