There were 40 people in range of his voice.
40x30 = 1200 voip minutes. That's as much as I talk to my friends and family on my cellphone each month. All in 30 minutes. People were listening, they told him to stop or go away!
LL creates junk stats as a way of life. It counts "accounts" as people, when we know that most accounts are alts or bots, or inactive.
The voip stat, is a junk stat, in that there is demand for people to get on voice, but the people who are demanding it, in many cases, are not paying. It would be like counting reaching voice mail as "talking to someone." It is not true.
Since voice is on by default, many people who have no intention of using voice, are "receiving" minutes.
SL voice does not directly compare either to internet broadcasting, or to telephony. This is another case of Linden Lab creating a fictional market size, to get people to jump in. There is no such huge market here for voice. None. Now there might be a use for SL as a con call platform, but it is too much trouble right now to do that.