In another thread, this set of comments caught my eye:
A thin page may not be what you think.
Huge article websites lost massively due to PANDA where article pages have lots of text. The quantity of pages compared to the available link juice is the problem.
...we have all been PANDAized some just feel the effects more than others because of (for lack of better words) regurgitated pages to target every longtail phrase was the model of choice... but now it does not work.
That said... all the pages are still there (indexed) and if they deserved ranks they would each have a few links to them. Granted you can't develop 3 million links for 1 million pages but you don't need to... just pick your ponies wisely.
I think the author of this comment was suggesting that in the post-Panda environment, pages that have zero external links pointed at them are not as valuable for SEO purposes as those same pages were in years past.
Perhaps I'm misinterpreting him, but I think he's arguing (or, at least someone could plausibly argue) that if your site has 5,000 pages, but only 50 of those pages have strong enough content to attract external links, as a result of Panda your site no longer has an advantage over an equivalent 200 page site with 50 equivalent pages of equally strong content attracting an equivalent set of inbound links.
I have no idea if this hypothesis is true but I think there is enough merit to it to justify some deep thought.
What's intriguing is that, as a working hypothesis it provides some insight into some of the tactical issues we all face concerning where we should invest our efforts.
Should we improve our weak pages?
Kill them off entirely?
Focus our efforts on trying to attract links to just the 50 strongest pages, or a much wider set of pages?
The OP in this thread touches on one aspect of this thought process -- identifying pages that receive no inbound referrals from search engines.
But, clearly this is not the only thing to consider. For instance, are those pages being read by users reaching them from other pages on the site? Is the content on those pages helping support the overall "theme" of the site, and providing indirect support for the pages that are ranking?