A Karma or Credit system

Since ontline is a team knowledge collaboration tool. I think it would be a great idea to provide a karma or credit system.
To be specific:

• according to the users's contribution to the knowledgebase, e.g. active time consumed in editing or word counts of content creation, to grant the contributors some credits or karma.
• add a page to honor the top credits contributors. say this week, this month, and total contribution.

This will give the active-sharing team members a sense of honor and , thereby, stimulating creation and sharing of knowledge.

What do you think?