How about a scrabble system to fund Drobe. It works like this...
Each user buys credit that pays allows them to post messages.
Each letter is assigned a value - just like in scrabble.
When a user posts an item, the value of the letters used is calculated and that amount is deducted from the users remaining credit.
To improve the quality of postings, users can earn credits if other people give them a positive rating for the item they have posted.
Earn free credits by contributing articles to Drobe.
OK, my cut is just 10% credited directly to my posting credit...