If you visit Gamasutra, you’ll be able to read an article on about Spore’s in-game connectivity to the webserver and how other games can use this method to provide new and refreshing gameplay.
Of course, in some games, gameplay and editing are more closely intertwined than they are in Spore. For example, gameplay in SimCity consists primarily of using an editor-like interface to build a city. Other examples of such games include Dungeon Keeper (dungeon customization tools), Tecmo’s Deception (trap placement), and The Incredible Machine (placement of objects).
These types of games, and any games where players can shape a game world into something unique, are usually well-suited for an automated content-sharing system like Spore’s.
While created content in Spore has little value beyond visual variety, user creations that are made through gameplay, affect gameplay, and are noticeably distinct from one another can add significant value and increase a game’s life span.
For instance, if SimCity were designed such that interactions with neighboring cities were complex and varied with the nature of those cities, user-created cities could keep those interactions interesting and unpredictable across many games.