While I don't agree with the entirety of this Wall Street Journal article, there are a few good ideas in there, such as:

• Use your subtitle to leverage the brand of top clients, for example: “CFO of Acme Accounting, financial advisers to Target.”
• Use the "hive mind" effect of LinkedIn groups to sound out new tools or ask for expert advice.

My issue with the article is that it underestimates the power of social selling, and overestimates the power of your network:

"It’s great to have collegial relationships with other people in your field. But when connecting on LinkedIn, it pays to be a little cutthroat. If small-business people accept collegial connection requests from people who work for competitors, they are making their entire network accessible to the competition."

It works both ways after all - yes you make your connections available, but so are theirs.

I also think the author has the wrong end of the stick when they say:

"By all means, cross-post the occasional article or update to LinkedIn, but focus on it as a source of connections and expertise—not as a way of building an audience or brand awareness."

Surely, sharing relevant articles is a way of nurturing your connections and demonstrating your expertise? It doesn't have to cost the earth to share this content to LinkedIn either.

As with all social networks, some caution is advisable, but there's no need to huddle over your notes to stop your neighbour from copying. Go on, share with the class!