Seth Godin's Blog: The circles: (no more strangers), 2010-May-17, by Seth Godin
More strangers to pitch your business, your candidate, your non-profit, your blog... More strangers means more upside and not so much downside. It means growth.
The problem is that strangers are difficult to convert. And the other problem is that they're expensive to reach. And the hardest problem is that we're running out of strangers.