The revenue model for a Commercial Site that lets users play EdUGames for free is advertising, sponsorship and information mining.
Some of the most obvious Commercial Sites possibilities are directed at people studying for a qualifying exam such as a professional license. The sponsors or advertisers can be companies interested in target marking to the particular professional.
A unique opportunity that avails itself to EdUGames is the ability for the program to choose the advertiser as a function of the player's ability. As an example: A player that does well on the Drivers License Game might see an ad for Car Insurance and a player who does poorly, an ad for Driving School.
Another unique thing about using EdUGames is that the sponsoring enterprise has a chance of introducing their product into the game itself for an additional fee. And lastly, the sponsor can gather useful information about the users such as what they know about a particular subject.