From a panel I was on at VRMS 2009 Emerging Marketing Technology Summit. This was part of my 5 - 7 minute overview - followed by discussion. Blog post: http://magnitudemedia.net/2009/09/how-big-are-your-virtual-ears/
Note: In 2010 we changed our company name from Uptown Uncorked to Magnitude Media to better reflect the wide variety of clients we serve.