Use the News and Discussion features of linked in to drive traffic to client Wordpress blog articles. It's a soft sell mechanism, a gateway for offers on the blog page. I am always pleased with the quality targeted traffic I get through this process.

If your tired of paying for $1.00 click thrus, the silly keyword scoring BS, rampant competitor click fraud, and not knowing anything about your traffic unless it converts, switch tactics.

I don't give a hoot about how Linked In makes its buck. A free account allows you to join 50 groups. If you setup a profile aimed at your target demo, and then join the right groups, you can post a weekly blog article notice that gets seen by 250k+ real human beings that actually converse about the topics you write about.

If you are a smart cookie you can leverage low cost labor for about $25 a week to write the article, post the notice across 50 groups, and average about 5000 real nice visitors a week. No click fraud, engaged readers, 1-2% conversions for your paying adv's. What would the same 20,000 clicks cost you on Google?

That's what Linked In is good for...

And Twitter too...

Facebook, not so much...

Facebook is useless for this, as a personal account maxes at 5k. Useless.