Labor-Value Currency + Freelancing Marketplace

[bitbor]

Why not creating a pre-mined currency which would only be tradable in a freelance marketplace ? The currency would then be linked to human's labor and work is the only way it can be traded for.
If you heard about the economist Adam Smith, you might understand what I am talking about. Any value is generated by human's labor (even bitcoin or any google search) and I was wondering why isn't there any product yet. Do you think this can work? I plan to prohibit its trade on marketplace to don't mix its value with the trading side, which would require another coin.
Would be happy to get your thoughts about this...