LinkedIn knows exactly how many people will hand over full control of their email if it means that they have a better chance of finding a better job.
Just doesn't seem like the greatest marketing strategy at the moment :-)
"Silicon" Valley is working on spy tools and innovative ways to get more people to click ads.
They probably do. And that guy probably got overruled by another guy who said, "Forget that naysayer and instead think about how much more aggressively we can market ourselves and how much more money we can make..."