I'm with Greenie...it's a good faith effort thing.
Kinda like having a bouncer at the door of your strip club who lets everybody in. But before doing so, he warns them there are naked ladies inside
Really no reason for it to have detrimental effects on se traffic, since a lot of traffic comes to interior pages anyway. And nope, no bouncer on these pages...he can't help it if they sneak in the side doors