It was indeed, look at the graph below.The speed of downloads has gone back again to values ranging between 200 and 500 downloads per minute depending on the hour of the day. It had been as high as 1400 downloads per minute after launching the campaign!
There have been (my estimate from the graph) 20 million additional downloads! In normal times 1 out of three corresponds to a new username. Let us even suppose that it was 2 out of 3 during that small period, thus 13 million North Americans registered a username. From other public Skype staff comments and numbers that I could collect, I estimated that less then 1 out of 10 becomes a regular user! So my estimate is: less then 1 million new regular North Americans users were added to the Skype Cloud due to the free SkypeOut Minutes campaign!
Not a big deal!