Stuart Henshall, Skype Journal, citing EuroTelcoblog:
At c30m registered users, Skype would appear to have penetrated 20% of its addressable market, and with around 2m concurrent users, more than 1% of the world's broadband population is running Skype at any given time.
… Despite 30m+ MSN video users no one ever talked about giving up the phone for it. Thus the numbers I'd like to see is Skype share of IM voice minutes, share of voice initiated sessions, and lastly share of messaging occasions. While I'm sure Skype has only a small share amongst text / chat sessions its share amongst voice initiated sessions should have made the other IM clients wake up by now.
I am only now making much use of IM, and do so via Skype.
Bill Campbell, also posting at Skype Journal:
The MSN + LogiTech Partnership raised the bar for Skype Video with their public release of MSN Messenger 7.0. Full screen video without pixelation. Excellent audio-video lip sync, modest bandwidth (audio + video at 80 kilobits per second) a frame rate high enough to pick up blink of an eye, CPU Utilization of 10 to 12 percent (using a AMD XP 3000+ CPU) and resolution that allowed my Skype buddy in Romania to read a document with 10 point text. The audio still sucks comparpared to Skype, but is a vast improvement over previous versions. It was quite useable. It was simple to set up. No ports to forward. … Truly an amazing product.
With Apple's Tiger-iChat and now MSN 7.0 Skype will be feeling the heat. Will they push out a quick and dirty beta to show they have video or will they give users a video conferencing system that really contributes to the Skype user's experience?

