We've gotten about 50 live viewers on our uStream, so I think this could get just as many. It's not a huge number but if someone hosts on a regular basis (daily) then the number would rise. I can see 100-150 live listeners on something like this. Then the recorded viewing would be watched as well. Some of our recordings got 600 views in a few days - not a huge number but it's not bad, especially when we're not doing it regularly.