Actually, my biggest concern has always been it's more face time on Google, less face time on our sites, more ad opportunity for Google, less ad opportunity for us.
That's the common thread that ties everything about Google since 2007-2008 when their natural growth stopped. They want people to start previewing site after site and maybe they'll click on ad instead. There isn't much more left to rig, one more Panda and the Senate might very well call the algo team so they try these tricks, each designed to send us less and less click.
Maybe an interstitial after clicking on our site link:
Are you sure you want to go there and not check these wonderful ads of ours?