WCF : Why Creating a ChannelFactory is more consuming that actually create the channels

I understand that the ChannelFactory creates the network connections and that the channel indeed act as a lock for one connection during one call. Can someone confirm, give some details?

Not exactly what you are looking for, but the best article I know of:

http://blogs.msdn.com/b/wenlong/archive/2007/10/27/performance-improvement-of-wcf-client-proxy-creation-and-best-practices.aspx