[sithadmin]

The problem with this idea is that it will just be abused for SEO spam junk, and you'll have to default to hiding all content with the 'non notable' bit from discovery by default lest the entire ecosystem get dragged down by the pollution. At this point, you might as well delete the content entirely, because it's just taking up space and not contributing to the experience for the vast majority of users.

[jacquesm]

I think there is a pretty easy to distinguish difference between 'SEO spam junk' and 'non notable' but if you're worried about that you could always have 'non notable' default to all outbound links to be 'nofollow'. For every problem there is a solution, if you want to solve it. I've seen and heard just about every excuse possible why particular things should be 'non notable' but not a single one that has stood up to scrutiny, it always seems to in the end boil down to 'because we say so'. Which is a pity because ultimately 'notability' is as much in the eye of the beholder as it is something objective and what is non-notable to one large group may well be notable to another. And if that first group is over-represented amongst the wikipedians then that's the end of that, no matter how important something really is.