… shared the newsletter of one client with another.

That helped in a few ways:

First, it was useful and appropriate information for the recipient (I forwarded it because the topic happened to be relevant).

Second, it raised the visibility of the person who wrote it.

Third, it helped me, because when you connect two people like that, both appreciate it.

“Social media” is more than just blasting people with a bunch of updates.

The point, it seems to me, is to be social (and relevant).