Second Life bloggers published numbers regarding the volume and some statistics about the inworld economy. It is very well known that virtual economies have become rather serious subject of studies, and from this point of view the data exposed might surprise you. In any case, here they are :

User-to-user transactions within Second Life total $350 Million in 2008. They were generated basically by virtual goods entrepreneurs, landowners, inworld builders and service providers. Of this money, $100 Million was sucked out of the economy via the Lindex exchange.

Top earners in Second Life (excluded Linden Lab, of course, it would be difficult to imagine they don't get respectable profit out of this money) are, in order, land owners, content creators and event managers, with a tendency that proves land and real estate activities to be the best business over the years.

In comparison with the real economy, the virtual one (at least in Second Life) seems to be doing pretty well. Accordingly to the expectations, 2009 should be a year of growth, bringing the transaction volume to $450 Million (over 20%). This growth is due to the fact that the number of users is constantly increasing, as well as the repeat log-ins (residents who stay after joining).

The article also reveals the results of a survey of business owners carried out in late February/early March. 64% of them claim to  generate positive net income from the products/services they sell. Optimism reigns!