It's all about staying-in-touch, "identifying" with your peers, and so on.
I'm always on the lookout for that little something - call it a stocking-stuffer - that I can use to touch my contacts.
Once you get into it, they pop up everywhere, articles in online newspaper stories, opportunities for business or pilot studies, jobs ...
A common incoming email, for me, is a job, forwarded by email from a colleague.
The job doesn't fit, because it states explicit requirements for a skill I don't have, and which is an essential requirement for the position.
But who do I know who is in transition, looking for work, contemplating freelance work?
I can send the email, personally address (so it's four emails leaving my desk, not one email with four BCCs), and presto! Four contacts have been touched today.
That was easy.