Seems sort of silly at this point. But with enough demand for more unskilled labour online, it might become something more substantial.

From the paper: " The rather wobbly-legged best guesses for 2008 are that 400,000 gold farmers earning an average US$145 per month produced a global market worth US$500m; but we could easily more than double the latter to over US$1bn. There are probably 5-10m consumers of gold farming services. "