The housing boom is alive and well—online. After an investment of $9.95 a month for more than two-and-a-half years, a virtual real estate agent has become a millionaire by selling virtual real estate. Anshe Chung, a prominent avatar in the Second Life virtual world, claims to be the first online personality with a net worth of over $1 million in U.S. dollars.

There may be other sizable fortunes based on virtual assets, but virtual magnates tend to keep quiet about their financial success because online game companies have traditionally frowned upon selling virtual goods and services. While there's a market for virtual world items in many popular online games, such transactions are typically contrary to the games' terms of service.

But Second Life has no such qualms about commercializing its digital world. And some companies like Sony have bowed to the inevitability of selling virtual goods and opened their own online markets to get in on the action.

Chung's holdings, which belong to Chinese-born German citizen Ailin Graef, include 36 square kilometers of imaginary land, several million Linden dollars (the Second Life currency), virtual stores, and virtual stock investments in Second Life companies. The estimate of her net worth reflects the current exchange rate for Linden dollars and the price for virtual goods in U.S. currency.

Graef built her avatar's empire by buying virtual land, subdividing it, and reselling or renting it. Her online business has become a tangible force in the real world, giving rise to a spin-off corporation, Anshe Chung Studios, which develops 3D environments for various commercial and educational applications. Graef runs Anshe Chung Studios with her husband, Guntram Graef, who serves as CEO.

Anshe Chung Studios is based in Wuhan, China, and currently employs 25 people. The company is seeking to expand its workforce to 50 people.

The lasting value of Second Life merchandise was called into question earlier this month with the release of a software program called CopyBot that let users clone objects in the virtual world. Graef's net worth may be somewhat protected since the program can't expand the amount of available land in the world, but it may decline if free copies of digital items affect sales at the virtual shops in which she has a stake. Her net worth may also diminish if recent Congressional interest in virtual economies results in virtual taxes.