GoldenTowns.com is a game where you can play for free and eventually start earning real money in exchange for in-game gold.
In this game, you control and build your small village into a major city with military and political influences. Once you have enough resources, you can start to mine in-game gold that is backed by a fixed supply of real gold. Whenever you want, you can cash out for a profit.
The game owners make money because there are options to 'speed up' tasks in-game (such as building roads) by paying in-game gold (which can also be bought with real money). You can make income by not investing a dime, however, it will just take a long time. If you're interested, feel free to sign up