How should Extra Stages/Screens be implemented?

[Hop]

As I have been designing a few Extra screens for my game I started to like them more than most of the screens I had in the main game. So my question is why have Extra at all? If you like the screens why not just put them in the main game instead of potentially locking off the best content. I like the idea of finding secrets in order to unlock an extra stage, but realizing then that most players would never see it is discouraging. I can see it as a good reward for dedicated players, but with new games coming out everyday it's hard to retain an audience for very long.

[Cantavanda]

Even though not many people will find them, I still love extra or secret rooms/screens.
You could put down small tips, and so a little few more people will find them, not a problem to me.

[Kyir]

Why not? Enjoyment for the player is probably #3 on my list of reasons for game making, enjoying myself is definitely higher, and hiding secrets is fun.

[lawatson]

I usually make games for myself to play, and if it's good by my standards, I go with it.

[Denferok]

You should be creating a game that is fun for you to play. If you like secret hunting you should go with it.

[zaphod77]

Having an awesome secret area, especially one that's not too hard to find, will encourage the player to go secret hunting.

Awesome secrets make secret hunting more fun.