Skype users have generated a call volume of 100 billion minutes since inception. Skype has 276 million registered users. The company started operations around August/September 2003. I worked the subscriber base backwards and got an average monthly growth rate of around 9% in registered users. That also gives an average minutes of use (MOU) at around 33 per month per registered user. Obviously if you consider just the active subscriber base, that average monthly MOU will go up substantially. So how to interpret the 33 minutes/month figure?
Interpretation 1: Skype is not just a pretty face. It is actually being used. The MOU may not be as close as in VoBB services from telcos, but the 33 minutes per month is not bad for a soft client. Keeping in view the fact that most Skype traffic is long distance, I think the usage matches that on PSTN.
Interpretation 2: MOU figure is digestible, not wild. Commodity telecom services are price inelastic and end users do not tend to increase the calling minutes proportionately as the price goes down.
Interpretation 3: Assuming all 100 billion minutes represent traffic substituted from TDM networks (and further assuming that the split of the substituted TDM traffic would have been 95% long distance and 5% local with long distance calls costing 2 cents per minute to consumer), Skype has cost the industry around $1.9 billion. That is the money Skype has spent building its brand over the years.
Obviously not all 100 billion minutes represented traffic substituted. So don’t read too much in the figures. It is actually quite possible that Skype stimulated additional traffic on TDM networks.