The 75% rule

It is true in business and I suspect it is true in all social groups from churches to FaceBook and the like. If you want to make the most of these networking opportunities (and they are networking events) you should spend 75% of your time with people you don't know. Most people I know spend most if not all of their time with the people they already know. How much bigger would you social world be if you followed the 75% rule?