At 40m minutes per day, for what it's worth, Skype is currently generating a level of traffic comparable to 15% of the daily fixed line traffic for the entire French market in Q3 2004. Another way of looking at it is that Skype traffic is nearly equal to the combined outgoing fixed line minutes to mobile and international numbers from the French PSTN.

Based on these same stats, I work out that French fixed line channels (33.6m) and mobile users (42.3m) generated just under 13 minutes per day of combined outgoing voice traffic in Q3 (7.9 per day for fixed, 4.8 for mobile). Just how many Skype users there are in a given day, we don't know, but currently I see 1.7m users logged on. If we were to take a stab at an actual daily user figure of three times that level (this is based on a crude segmentation of a 24-hour day into the three big broadband population centers), it implies that the average Skype user generates 7.9 minutes per day of voice traffic - in other words, a level comparable to that of the average French PSTN user.
EuroTelcoblog