Allowing players to take advantage of the interactive aspects (such as in an mmo)
This is a new sight for me. And maybe yes, it could partially substitute the multiplayer. Why? Because it requires some kind of AI. If it was hardcoded it would be boooring.
I mentioned it because in the game system I am toying with I have one aspect I call philosophy that shouts for such an utilization. Philosophy meaning here is conditionality of acting, purpose, boundedness of tools (would you torture?) etc. This aspect can be thought as a one of the resouces to solve problem (king marries neighbours daughter, make enemies fight against each other etc.)
Technically its a tree with defined processes. The things for example I want it should capture are why Tom Sawyer could make an interesting deal when painting the fence, why otherwise weak will person can sacrifice himself, or strong will person cannot resist some pleasure.
To make an information valuable there must be set of knowledge (updated in time) for the characters, system of costing the information, system of propagation of the information with distorsion - by purpose or naturally. I am sure I would go rofl if some Merchant asked me - umm, have heard you bought a ton of garlic from Greedy. Are you really founding garlic spa?